Question

Determine as raizes das equações a)x²=81 b)x²=100 c) (x-7)²=0 d) (x+5)²=0

Answer 1

a)x²=81 ==> x = +/- 9
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b)x²=100 ==> x = +/- 10
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c) (x-7)²=0 ==> x² - 14x +49 = 0

Δ = (-14)² - 4.1.49= 196 - 196 = 0

x = 14+/- 0 ==> x1=x2= 7
           2
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d) (x+5)²=0 ==> x² + 10x + 25 = 0

Δ = (10)² - 4.1.25= 100 - 100 = 0

x = - 10+/- 0 ==> x1=x2= - 5
           2