Question

What is 5(3m - 4)^2 - 2(3m - 4) - 16 = 0, if u = 3m - 4

Answer 1

I only got up to 5u^2 - 2u - 16 = 0

Answer 2

i hate factoring, don't you?

Answer 3

same as last time list out the factors

Answer 4

of both the first and last terms.

Answer 5

I don't really get it this time

Answer 6

too many choices
\[(5u+a)(u+b)\] i would solve the quadratic equation, then i would know what the factors are

Answer 7

it's alright, the above would work too.

Answer 8

5 only has 5x1

Answer 9

Yes

Answer 10

what about 16?

Answer 11

yea, but 16 has a bunch
1, 16,
2, 8
4, 4

Answer 12

and also
16, 1
8, 2
4, 4

Answer 13

you try to find one pair that when times 5 the numbers are close

Answer 14

and it is negative, so there are really twice as many
ick ick ick

Answer 15

I really don't know. I hate this stuff!

Answer 16

especially when it's negative let's say using your brackets:
(5u+a)(u+b)

Answer 17

either 5b>a
or a>5b both without the negative sign

Answer 18

I don't get it

Answer 19

i'll give an example

Answer 20

say:
x-3x-4

Answer 21

-4=-4x1

Answer 22

and -4+1 =-3

Answer 23

do you get this?

Answer 24

Yes

Answer 25

okay, now let's work with -16
-16=-16x1
= -8x2
=-4x4 etc

Answer 26

you multiply 5 into one number of the pairs

Answer 27

ok

Answer 28

try them, add them up with the negative sign, and try to find -2

Answer 29

Ok. Thanks!

Answer 30

you got it? gr8!

Answer 31

so what's the answer?