Question

Resolva as equações incompletas:
a) x²-36=0
b)x²-81=0
c)2x²=128
d)3x²-20=280
e)x²-2x=0
f)x²+6x=0
g)2x²-12x=0

Answer 1

a) x²-36=0 ==> x² = 36 ==> x = +/- 6
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b)x²-81=0  ==> x² = 81 ==> x = +/- 9
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c)2x²=128 ==> 2x² = 64 ==> x = +/- V32 ==> x = +/- 4V2
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d)3x²-20=280 ==> 3x² = 280+20 ==> x² = 100 ==> x² =+/- 10
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e)x²-2x=0 = 0

x(x-2) = 0 ==> x1 = 0

x2 - 2 = 0 ==> x2 = 2
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f)x²+6x=0

x(x+6) = 0 ==> x1 = 0

x2 + 6= 0 ==> x2 = 2
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g)2x²-12x=0

x(2x-12) = 0 ==> x1 = 0

2x2 - 12 = 0 ==> 2x2 = 12 ==> x2 = 6