X2 plus 3x-7 equals 5x plus 8?

Answer 1

x^(2) + 3x - 7 = 5x + 8

Subtract '8' from both sides

Hence

x^(2) + 3x - 15 = 5x

Subtract '5x' from both sides

Hence

x^(2) -2x - 15 = 0

It is now in quadratic form and will factor.

Hence

( x -5)(x + 3) = 0

x = 5

& x = -3

Answer 2

x2 + 3x - 7 = 5x + 8; thus,

x2 + 3x - 7 - 5x - 8 = x2 - 2x - 15

= (x - 5)(x + 3) = 0.

Therefore the solution is

x = 5 or -3.