Question

determine as raizes da esquacao X2-9x+20=12

Answer 1

Δ = b² - 4 x a x c 
Δ = (-9)² - 4 x 1 x 20 
Δ = 81 - 80 
Δ = 1

x = (-b ± √Δ) / 2 x a

x' = (-(-9) + √1) / 2 x 1
x' = (9 + 1) / 2
x' = 10 / 2
x' = 5

x'' = (-(-9) - √1) / 2 x 1)
x'' = (9 - 1) / 2
x'' = 8 / 2
x'' = 4

S = {5; 4}