Question

Calcule as raízes das seguintes equações a) (x+2).(x-16)=_32 b) (x+7)²=49+8x

Answer 1

a)(x + 2).(x - 16)= - 32
    x² - 16x + 2x -32 +32 =
   x² - 14x = 0

b)(x + 7)² = 49 + 8x
    x² + 14x + 49 = 49 + 8x
    x² + 14x - 8x +49 - 49=0
    x² + 6x = 0
   

Answer 2

a) (x+2).(x-16)= - 32

x^2 - 14x - 32 = - 32

x^2 - 14x - 32 + 32 = 0

x^2 - 14x = 0

x(x - 14) = 0

x1 = 0

x2 - 14 = 0 ==> x2 = 14
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b) (x+7)²=49+8x

x^2 + 14x + 49 - 49 - 8x = 0

x^2 + 6x  = 0

x(x + 6 ) = 0

x1 = 0

x2 + 6  = 0 ==> x2 = - 6