Clara writes the equation (x – 13)(x + 8) = 196 to solve for the missing side length of a triangle represented by the factor x + 8. What is the missing side length represented by x + 8 units of the triangle? A. 7 B. 15 C. 20 D. 28

Respuesta :

(x – 13)(x + 8) = 196
x * x + x * 8 - 13 * x - 13 * 8 = 196
x² + 8x - 13x - 104 = 196
x² - 5x - 104 - 196 = 0
x² - 5x - 300 = 0

The missing side length is 28