Question

Factorise x²+7x-8 step by step

Answer 1

Answer:

x-1,x+8

Step-by-step explanation:

Given x2+7x−8

Note that the sum of the coefficients is 0. That is 1+7−8=0.

So x=1 is a zero and (x−1) a factor:

x2+7x−8=(x−1)(x+8)

The linear factor (x+8) can be constructed by looking at the coefficients of x2 and the constant term −8 that we want in the product:

Since the coefficient of x2 is 1 in the product, we require a coefficient 1 for x.

Since the constant term is −8 in the product, we require a constant +8 in the factor which will become −8 when multiplied by −1.

Answer 2

Answer:

(x-1)(x+8)

Step-by-step explanation:

x^2+7x-8

x^2-x+8x-8

x(x-1)+8(x-1)

(x-1)(x+8)