Question

Como resolvo? A-) (x+5)²=25 B-) 2(X²-1)=X²+7 C-) 1+1

Answer 1

A) ( X + 5 )² = 25
X² + 2 X.5 + 5² = 25
X² + 10 X + 25 = 25
X² + 10 X + 25 - 25 = 0
X² + 10 X = 0
X( X + 10 ) = 0
X = 0
X + 10 = 0
X = - 10
S = {0 ; -10 }
B)2.(X² - 1 ) = X² + 7
2 X² - 2 = X² + 7
2 X² - 1 X² = 7 + 2
X² = 9
X = + OU - √9
X = + OU - 3
s = { + 3 ; - 3 }
c)1 + 1 = 2

Answer 2

a)

= (x+5)²=25
x² + 2.5x + 25 = 25
x² + 10x = 25 - 25
x² + 10x = 0
x.(x + 10) = 0
x = 0
x + 10 = 0
x = - 10

R.: x = 0 e x = - 10
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B)
2(x² - 1) = x² + 7 
2x² - 2 = x² + 7
2x² - x² = 7 + 2
x² = 9
x = √9
x = + 3 e x = - 3

R.: x = 3 e x = - 3

c) 1 + 1 = 2