Question

I have to factor this expression (ax^2+bx+c) and I’m having some trouble. Can someone help me with this?

Answer 1

Ok so 3x-40=-120 and the middle number is -7 so the two numbers will have to multiply to -120 and add to - so those numbers would be 15 and-8 so then we will factor by parts so 3p^2+15p-8p-40 then section into brackets (3p^2+15p)(-8p-40) out of the first bracket you can factor out 3p and on the second bracket you can factor out -8 so you are left with 3p(p+5)-8(p+5) the combine 3p and -8 so (3p-8)(p+5)

Answer 2

3p^2 - 7p -40

Factor -7 out of -7p and rewrite -7 as -15 +8:

3p^2 +(-15 +8)p -40

Apply distributive property:

3p^2 -15p +8p -40

Group the first two terms and the last two terms:

(3p^2 -15p) + (8p-40)

Factor out the GCF from each group:

3p(p-5) + 8(p-5)

Factor the polynomial by factoring out the GCF (p-5)

(p-5)(3p+8)