the product of a number and the sum of the number and five is eight

Answer 1

Let X = the number

X(X+5)=8

X² + 5X -8 = 0 Can't factor, so use quadratic formula or complete the square

X=[-5+ or - sqr(25+4(8))]/2 = -5/2 + or - 1/2 sqr57 =-2.5 + or - 7.55/2 = -2.5 + or - 3.775

X= -6.275, 1.275

complete the square method

X² + 5X + 25/4 - 8 - 25/4 = 0

(X+5/2)² = 57/4 take the square root of both sides

X = -5/2 + or - (1/2)sqr57 = -6.274, 1.275