factor. check by multiplying.?

Question

3x^2+9x-12
a) 3(x^2+6x-9
b) 3x(x+3-4)
c) 3(x^2+3x-4)
d) 3(x^2+9x-12

Answer 1

C is correct but not complete... only the 3 is factored out... the real answer would be:

3(x-1)(x+4)

Answer 2

For a multiple choice question c) looks promising to me.

Find the largest number that goes into 3, 9 and -12

"take it out of each of the terms" and put it outside a bracket.

3(......................)

3 into 3x^2 goes x^2

3(x^2................)

3 into +9x goes 3x

3(x^2 +3x .........)

3 into -12 goes -4

3(x^2 +3x -4) This is option c)

And just to check that it "works", you can multiply through the whole bracket (multiply each term in turn) by 3 and get the question you started with.

Answer 3

C

Just divide out the 3 of each component of the equation to arrive @ answer C

Answer 4

that wud be letter c
and yes, u can check by multiplying (distribute the 3)

if u multiply it... this is wat u get for each:
a. 3x^2+18x-27
b. 3x^2+9x-12x
c. 3x^2+9x-12
d. 3x^2+27x-36

so u can obviously see that the answer is C

hope this helps!!