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Qualification => University => Topic started by: Tohru Kyo Sohma on August 12, 2012, 06:43:21 pm

Title: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 12, 2012, 06:43:21 pm
Ok...so i will soon be starting my university and i have to appear for my placement test!
The test is for Business maths and English
I have tried the maths questions from a sample test paper and am finding it difficult as i haven't practiced maths for a year!
Please help me out with my questions!
 
1. Evaluate (3x^4y^-8/5x^-2y^4z^2)^-2?
2. Find the domain of the function f(x)=2 ?-2+x

Please help me out!
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 12, 2012, 06:51:11 pm
Give me an hour
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 12, 2012, 07:21:31 pm
Try this. The second question is not clear. You can post again.
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 12, 2012, 07:56:47 pm
Thanks astarmathsandphysics
I got how to do the first one
the second one where a question mark appears it is supposed to be a root i copied a symbol but it didn't appear!
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 12, 2012, 08:02:52 pm
If  root x then domain is x>=0
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 05:53:55 pm
One factor of 18x^2 -32 is
(a) 9x-32
(b) 9x-16
(c) 3x-2
(d) 3x+4
(e) none of the above
?
which one is it?
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 06:09:23 pm
If 2a-b/b=3 then b/a is equal to:
a. 2
b. -0.5
c. 0.5
d. -2
e. none of the above

I think its C
i got this by apply the algebric formula and got a=4 b=2
what do you guys think?
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 06:40:14 pm
One mo
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 06:43:03 pm
18x^2-32=2(9x^2-16)=2(3x-4)(3x+4)
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 06:44:58 pm
(2a-b)/b=2a/3-b/b=2a/b-1=3
2a/b=4 so a/b=2 so b/a=1/2=0.5
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 06:46:48 pm
18x^2-32=2(9x^2-16)=2(3x-4)(3x+4)
so it's D?
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 06:47:46 pm
(2a-b)/b=2a/3-b/b=2a/b-1=3
2a/b=4 so a/b=2 so b/a=1/2=0.5
so c is right?
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 06:51:11 pm
Solve 2x^2+6x-3=0
options:
a. x=(-3+- root of 15)/2
b. x=(-3+- root of 3)/2
c. x=(3+- root of 15)/2
d. x=-3+-root of 15
e. none of the above

I think its E?
Is it right?
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 07:38:45 pm
D then C for the first 2.
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 07:48:08 pm
D then C for the first 2.
For the third I make it A using the quadratic formula.
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 23, 2012, 08:57:40 pm
D then C for the first 2.
For the third I make it A using the quadratic formula.
Quadratic formula
x= (-b+- root of b^2-4ac)/2a
x= -6+- root of 36+24 / 2*2
x=-3 +- root of 60 /2
root of 60 is also 2 root of 15

how A then?
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 23, 2012, 10:00:30 pm
sqrt(60)=sqrt(4*15)=sqrt(4)*sqrt(15)=2 sqrt(15)
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 24, 2012, 06:06:44 pm
(-6+-sqrt(60))/4 =(-6+-2sqrt(15))/4=(-3+-sqrt(15))/2
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 01:52:54 pm
(-6+-sqrt(60))/4 =(-6+-2sqrt(15))/4=(-3+-sqrt(15))/2
wait how did the 2 disappear from there!
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 02:20:37 pm
1.Using a phone card to make a long distance phone calls costs a flat fee of $0.85 plus $0.19 per minute starting with the first minute. What id the total cost a phone call which lasts 8 minutes?
a. $2.37
b. $6.00
c. $8.16
d. $1.52
e. none of the above

I THINK ITS A


2. A survey of 250 residence indicated that 170 owned a TV, 130 owned a DVD and 80 owned both TV and DVD. How many donot own a TV or a DVD?
a. 50
b. 90
c. 30
d. 80
e. none of the above

I THINK ITS C[/b]
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 02:26:30 pm
The 2 disappeared because I cancelled every term by 2
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 02:27:46 pm
0.85+8*0.19=2.37
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 02:32:12 pm
I drew a Venn diagram see attachment.
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 03:16:26 pm
I drew a Venn diagram see attachment.
0.85+8*0.19=2.37
Thanks

The 2 disappeared because I cancelled every term by 2
can we cancel the same terms from numerator together?
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 03:48:42 pm
(3A-4B)^2=
a. 3a^2-4b^2
b. 9a^2-16b^2
c. 9a^2+24ab-16b^2
d. 9a^2+24ab+16b^2
e. none of the above

I think its E
i got my answer as 9A^2-24AB+16B^2
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 04:13:37 pm
Solve the equation x(x-12)=-20. the sum of the 2 solution is?
a. 10
b. 12
c. 14
d. 8
e. -8

I think its B
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 05:13:21 pm
How many solutions has the system 2x-3y=5    2/3x=y+5/3
a. None
b. exactly one
c. exactly two
d. infinitely many
e. none of the above

I have no idea how to do it?
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 07:12:00 pm
Pls help me out
I have my exam within 10 hours

f 9^x-2y =81 then 4y-2x =
a.1
b.3
c.-4
d.4
e. none of the above
I think its C? Am i right?

Q. If f(x)-3x^2 -1 then f(h+1)=
a. 3h^2+6h+4
b. -3h^2+6h-4
c. -3h^2-6h -4
d. -3h^2
e. none of the above

Q. (x^-3   x^2 / x^5)^2/3 equals to
a. x^4
b. 1/x^4
c. 1/x^3
d. x^3
e. none of the above

Q. If p^2=1 and q^2=9. Then the smallest values of p-q is
a. -4
b. 8
c. -10
d. 4
2. None of the above

Q. 5/9x^2 +1/6x =1
a. 10+3x/18x
b. 10+3x /9x
c. 10+3x/18x^2
d. 10+3x/9x^2
e. none of the above

Q. 2/x +3/2x -4/4x=
a. -24/8x^3
b. 24/8x^3
c. 1/7x
e. 9/7x
e. none of the above
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:01:48 pm
You can canel thoughout by 2 for example (4+6)/4=(2+3)/2
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:08:57 pm
the first three questions answered in attachment
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:17:32 pm
more answers
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:24:31 pm
yet more answers
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 08:40:45 pm
You can canel thoughout by 2 for example (4+6)/4=(2+3)/2
I see
the first three questions answered in attachment
Thanks alot for your help

more answers
Thanks again

yet more answers
Thanks yet again






I have 1 last question to ask
what is a domain of a function exactly?
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:42:29 pm
It is the set of values that can be put into a function
The domain of f(x)=sqrt(x) is x>=0 because you cannot take the square root of a negative number
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:44:01 pm
good luck
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 08:46:23 pm
It is the set of values that can be put into a function
The domain of f(x)=sqrt(x) is x>=0 because you cannot take the square root of a negative number
so the domain of the function f(x)=2 root of -2+x is?
a.x=2
b.x<2
c.x>2
d.x=>2
e.None of the above
Title: Re: Maths Help Needed :(
Post by: astarmathsandphysics on August 26, 2012, 08:47:21 pm
x>=2 actually but some say x>2
Title: Re: Maths Help Needed :(
Post by: Tohru Kyo Sohma on August 26, 2012, 08:48:39 pm
good luck
Thanks

x>=2 actually but some say x>2
i think so too