(8x+2)(12x-2)=120

Question

I need help in geometry

Answer 1

I would bet you're confused and told that the perimeter is 120.

P = 2(l + w)

P/2 = l + w

120/2 = 8x + 2 + 12x - 2

60 = 20x

x = 3

8(3) + 2 = 24 + 2 = 26

12(3) - 2 = 36 - 2 = 34

Answer 2

Are you asked to solve the equation??

If so, my method would be to first get it in "standard form": ax² + bx + c = 0

(8x+2)(12x-2)=120

expand:

96x² + 8x - 4 = 120

Factor out 4, and arrange in standard format:

24x² + 2x - 1 = 30

24x² + 2x - 31 = 0

Not factorable, so use the quadratic equation"

x = ( -2 ±√(2² + 4*24*31) ) / 2*24

x = ( -2 ±√(2980) ) / 2*24

x = ( -2 ±54.6 ) / 2*24

52.6 / 48, and -56.6 / 48