Question

Resolva as equações.COM OS CACULOS
a)x² - 90=31
b)5x² + 4=49
c)4x² - 27=x²
d)2x² + 11=x² + 12
e)5(x² - 1)=4(x² +1)
f)x(x+2)=2x + 25

Answer 1

Olá Thalita

a) 

x² - 90 = 31
x² = 121
x1 = -11, x2 = 11

b) 

5x² + 4 = 49
5x² = 45
x² = 9
x1 = -3, x2 = 3

c)

4x² - 27 = x²
3x² = 27
x² = 9
x1 = -3, x2 = 3

d)

2x² + 11 = x² + 12
x² = 1
x1 = -1, x2 = 1

e)

5*(x² - 1) = 4*(x² + 1)
5x² - 5 = 4x² + 4
x² = 9
x1 = -3, x2 = 3

f)

x*(x + 2) = 2x + 25
x² + 2x = 2x + 25
x² = 25
x1 = -5, x2 = 5

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