Question

B) X 2 - 3 X - 28 = 0

Answer 1

Delta= (-3)² - 4.1 . (-28)
Delta= -9 -  112
Delta= 121

X= -3X + 11 /2xa = 14/2 = 7
 X= -3X - 11 /2xa = 8/2 = 4
S= {7 e 4}

Answer 2

Δ = 9 + 112
Δ = 121

x = 3 +-√121/2
x = 3 +-11/2

x' = 3 +11/2
x' = 14/2 = 7

x'' = 3 -11/2
x'' = -8/2 = -4                      S = { -4 , 7 }             ok