Answer: x=4 or x=-10
Step-by-step explain: Factoring x2+6x-40
The first term is, x2 its coefficient is 1 .
The middle term is, +6x its coefficient is 6 .
The last term, "the constant", is -40
Step-1 : Multiply the coefficient of the first term by the constant 1 • -40 = -40
Step-2 : Find two factors of -40 whose sum equals the coefficient of the middle term, which is 6 .
-40 + 1 = -39
-20 + 2 = -18
-10 + 4 = -6
-8 + 5 = -3
-5 + 8 = 3
-4 + 10 = 6 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -4 and 10
x2 - 4x + 10x - 40
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-4)
Add up the last 2 terms, pulling out common factors :
10 • (x-4)
Step-5 : Add up the four terms of step 4 :
(x+10) • (x-4)
Which is the desired factorization