Solve x squared plus x equals 56?

Answer 1

(X +7) X-8)

Answer 2

The way to do this is get an expression equal to zero, then solve (in this case it's a quadratic), so either factor or use the quadratic equation. x2 + x - 56 = 0: Factors into: (x - 7)(x + 8) = 0, x = 7 & x = -8

To factor, find two numbers which when added equal 1 (the coefficient of the x term) and when multiplied equal -56. So one of the numbers must be positive and the other negative. Factor pairs of 56 are (1,56) (2,28) (4,14) and (7,8). Seven & eight are one apart, so if the seven is negative, they will add to equal 1. If either of the binomial factors is zero, then the result is zero, so for (x-7)=0, {x=7} solves it, and for (x+8)=0, {x=-8} solves it. Check your answers in the original equation, to make sure you did it correctly:

7^2 + 7 = 49 + 7 = 56 (check) (-8)^2 + -8 = 64 - 8 = 56 (check) STANLY WAS HERE