Question

Solve for k.
k² - 19k - 20 =0

Answer 1

k² - 19k - 20

(k-20) (k+1) = 0

k-20 = 0

k=20

k+1 = 0

k= -1

k= 20 and -1

Answer 2

k = -1, 20

Explanation:

k² - 19k - 20 = 0

k² + 1k - 20k - 20 = 0 ==> 1 * (-20) = -20 and -20 + 1 = -19

k² + k - 20k - 20 = 0

k(k+1) - 20(k+1) = 0 ==> factor and simplify

(k-20)(k+1) = 0

k-20=0 ==> k=20

k+1=0 ==> k=-1

k = -1, 20