Maths Help Needed :(

[Tohru Kyo Sohma]

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?

[astarmathsandphysics]

sqrt(60)=sqrt(4*15)=sqrt(4)*sqrt(15)=2 sqrt(15)

[astarmathsandphysics]

(-6+-sqrt(60))/4 =(-6+-2sqrt(15))/4=(-3+-sqrt(15))/2

[Tohru Kyo Sohma]

(-6+-sqrt(60))/4 =(-6+-2sqrt(15))/4=(-3+-sqrt(15))/2

wait how did the 2 disappear from there!

[Tohru Kyo Sohma]

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]

[astarmathsandphysics]

The 2 disappeared because I cancelled every term by 2

[astarmathsandphysics]

0.85+8*0.19=2.37

[astarmathsandphysics]

I drew a Venn diagram see attachment.

[Tohru Kyo Sohma]

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?

[Tohru Kyo Sohma]

(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

[Tohru Kyo Sohma]

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

[Tohru Kyo Sohma]

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?

[Tohru Kyo Sohma]

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

[astarmathsandphysics]

You can canel thoughout by 2 for example (4+6)/4=(2+3)/2

[astarmathsandphysics]

the first three questions answered in attachment