Question

Resolva as equacoes do 2° grau : a)2x2-3x=0. b)3x2-27=0.c)x2=10x+9=0

Answer 1

a)2x²-3x=0

x(2x-3) = 0

x' = 0


x" => 2x-3 = 0
2x = 3
x = 3/2

S = {0, 3/2)




b)3x²-27=0

x(3x-27) = 0

x' => x = 0

x" => 3x-27 = 0
3x = 27
x = 27/3
x = 9

S = {0,9}



c)x² + 10x+9=0

Δ = b²-4ac
Δ = 10²-4.1.9
Δ = 100-36
Δ = 64

x = [b±√Δ]/2a
x = [10±√64]/2.1
x = [10±8]/2

x' = [10+8]/2
x' = 18/2
x' = 9

x" = [18-8]/2
x" = 10/2
x" = 5

S = {5, 9}



Abraços õ/