Answer:
Step-by-step explanation:
5) n² + 8n - 20 = 0
Sum = 8
Product = -20
Factors = 10 , (-2) {10+(-2) = 8 and 10*(-2) = -20}
n² + 10n - 2n -20 = 0
n(n + 10) - 2(n + 10) = 0
(n + 10)(n -2) = 0
n + 10 = 0 ; n -2 = 0
n = -10 ; n = 2
Roots are : -10 , 2
6) x² + 10x = 0
x(x + 10) = 0
x = 0 ; x + 10 = 0
x = 0 ; x = -10
Roots: x = 0, -10
