Question

Could someone show me how to do these 5?
1. 9x^2 (x-2)-8x(x-2)
2. 2x^3 –x^2– 8x + 4
3. 3y^3– 6y^2 + 4y – 8
4. 4m^2+5m-9
5. 5p ^2+23p-42

Answer 1

What is the question asking? To factor or simplify?

Answer 2

factor

Answer 3

ok, the first one gives you the following:

9x^2 (x-2)-8x(x-2)

// factor out the (x-2)
(x-2) * (9x^2-8x)

// you can also factor out an x from 9x^2-8x
x*(x-2)*(9x-8)

Answer 4

@tomo so (x-2)*(9x^2-8x) is the answer?

Answer 5

well you can still factor an x out of the (9x^2-8x) so you would have
(x-2) * x(9x-8)

Answer 6

@tomo i just need #2 and #3 cuz i ended up figuring out how to do 4 and 5

Answer 7

2x^3 –x^2– 8x + 4

x^2(2x-1) + 4*(-2x+1)
x^2(2x-1) -4(2x-1)

// pull out a (2x-1)
(2x-1)(x^2-4)

Answer 8

3y^3– 6y^2 + 4y – 8

3(y^2)(y-2) + 4(y-2)

//pull out a y-2
(y-2)(3y^2+4)

Answer 9

@tomo could you show me #3 cuz i think i got it but i wanna make sure

Answer 10

im sorry i ment #2

Answer 11

// what we start with
2x^3 –x^2– 8x + 4

// pull out a x^2 out of the first two terms. pull out a 4 out of the second two terms.
x^2(2x-1) + 4*(-2x+1)

// pull out a -1 out the second two terms. this reverses the signs on the two last terms.
so instead of -2x+1 you have -(2x-1). this allows you to have a common factor of (2x-1)
x^2(2x-1) -4(2x-1)

// pull out the common factor of (2x-1)
(2x-1)(x^2-4)

Answer 12

omg im so sorry i keep getting my numbers all mixed up, ur probably annoyed cuz u just show me how to do #2 lol. i needed you to show me 4. sorry again @tomo

Answer 13

no problem.
// this one is a bit more confusing though.

Answer 14

@tomo i got (4m+9)m-1)

Answer 15

ok, so we start with

4m^2+5m-9

// for some reason, break up the 5m into 9m-4m. I don't know why, but it works.
4m^2+9m-4m-9

// so now this is something we can work with. pull a negative out of the -4m-9.
4m^2+9m-(4m+9)

// like you got.
(4m+9)(m-1)

Answer 16

hope that helps. gotta go to sleep now.

Answer 17

@tomo dude thank you so much, you have no idea how big of a help you were. goodnight!