Question

@mathmate

Answer 1

This is kind of what im working on
34 and 35 are the problem ones >_<

Answer 2

Yeah, they look difficult, but not really if you know
- cross multiplication
- FOIL
- solution of linear or quadratic equation in one unknown.

What you need to do is first cross multiply.
For #34,
you have
(x-3)(x+6)=x*x
use FOIL to expand both sides (if necessary)
x^2-3x+6x-18 = x^2
Cancel x^2
3x-18=0
and you can solve for the rest.

Answer 3

For #35, the steps are the same. But in the end, you need to solve a quadratic equation, either by factoring, or by the quadratic formula.

Answer 4

2x(9-x) 5(x+4)
18x-2x^2+5x+20
-2x^2+23x+20
this cant be right... :/

Answer 5

oh thats number 35 btw...

Answer 6

Don't forget the equal sign.
\(\large \frac{9-x}{x+4}=\frac{5}{2x}\)
Cross multiply:
2x(9-x)= 5(x+4)
Expand
\(18x-2x^2=5x+20\)
Transpose terms
\(2x^2-13x+20=0\)
I'll let you finish the rest using factoring of quadratic expressions.

Answer 7

(x-8)=0
(x-5)=0
x=8 x=5

Answer 8

Excellent! Well done! :)

Answer 9

:) thanks you!

Answer 10

You're welcome! :)

Answer 11

Think we can do one more? :) you can pick it :P it does not have to be from that page it can be made up :)

Answer 12

try:
(5x-8)/(x+1) = (3x-2)/(7-x)

Answer 13

\[\frac{ 5x-8 }{ x+1}=\frac{ 3x-2 }{ 7-x }\]
(5x-8)(7-x)=(x+1)(3x-2)
\[35x-5x^2-8~=~ 3x^2-2x+3x-2\]

\[ -2x^2-6+36x\]
divde all by -2
\[2(x^2+18x-3) \]

Answer 14

is it right so far?

Answer 15

Not sure after all divided by -2!

Answer 16

Would it just be 2? :/

Answer 17

(5x-8)(7-x)=(x+1)(3x-2)
Use FOIL
35x-5x^2-56+8x = 3x^2-2x+3x-2
Move everything to the right:
3x^2+x-2-(43x-5x^2-56)=0
8x^2-42x+54=0
Can you solve the rest?

Answer 18

4x^2-21x-27

i have no idea...

Answer 19

It's 4x^2-21x+27, and that makes a big difference, because then both m and n are negative!

Answer 20

I hate this! T_T
there is no solution am i right? :)

Answer 21

Since it is +108, the \(sum\) of m and n must be -21, and both m and n are negative (in order that the product be positive).
So check:
4*27 sum=31 too big
6*18 sum = 24 too big
9*12 sum = 21 Good!
So

Answer 22

(4x^2-12x)(-9x+27)
4x(x-3) -9(x-3)
(4x-9)(x-3)

Answer 23

please say its right! >_<

Answer 24

Yes, it's correct!, so x=? or ?

Answer 25

x=3
x=9/4

Answer 26

Excellent! both correct!

Answer 27

:)

Answer 28

:) thanks :)

Answer 29

You're welcome! :)
I think you are getting the hang of it pretty well!

Answer 30

:)