Respostas
Explicação passo-a-passo:
1) a) 2x² + 2x - 40 = 0
completa
b) - 4x² + 6x = 0
incompleta
c) 9x² - 4 = 0
incompleta
d) x² - x - 12 = 0
completa
e) 5x² = 0
incompleta
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2) a) 10x² + 3x - 1 = 0
a = 10
b = 3
c = - 1
b) x² + 2x - 8 = 0
a = 1
b = 2
c = - 8
c) y² - 3y - 4 = 0
a = 1
b = - 3
c = - 4
d) 7p² + 10p + 3 = 0
a = 7
b = 10
c = 3
e) - 4x² + 5x = 0
a = - 4
b = 5
c = 0
f) r² - 16 = 0
a = 1
b = 0
c = - 16
g) - 2m² = 0
a = - 2
b = 0
c = 0
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3) a) x² - 6x = 0
x.(x - 6) = 0
x' = 0
x - 6 = 0
x" = 6
S = {0 ; 6}
b) x² - 16 = 0
x² = 16
√x² = √16
x = ± 4
x' = + 4 ; x" = - 4
S = {- 4 ; 4}
c) x² - 1 = 0
x² = 1
√x² = √1
x = ± 1
x' = + 1 ; x" = - 1
S = {- 1 ; 1}
d) x² + x = 0
x.(x + 1) = 0
x' = 0
x + 1 = 0
x" = - 1
S = {- 1 ; 0}
e) 7x² - 2x = 0
x.(7x - 2) = 0
x' = 0
7x - 2 = 0
7x = 2
x" = 2/7
S = {0 ; 2/7}
f) 10x² = 0
x² = 0/10
x² = 0
√x² = √0
x = 0
S = {0}
g) 16y² = 9
y² = 9/16
√y² = √9/16
y = ± 3/4
y' = + 3/4 ; y" = - 3/4
S = {- 3/4 ; 3/4}