Question

Qual o valor de x em cada uma das equações a seguir?
A) X + 15 = 20 + 5
B) 3x = 12 + 6
C) 2x² = 8
D) 4x – 2 = 10

Answer 1

Resposta:

$x + 15 = 20 + 5\\\\25 - 15 = x\\\\x = 10\\\\10 + 15 = 25$

x = 10

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$3x = 12 + 6\\\\18 : 3 = x\\\\x = 6\\\\3x 6 = 18$

x = 6

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$2x^2=8\\\\\frac{2x^2}{2}=\frac{8}{2}\\\\x^2=4\\\\x=\sqrt{4},\:x=-\sqrt{4}\\\\x=2\\\\\:x=-2$

x = 2 e x = -2

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$4x-2=10\\\\4x-2+2=10+2\\\\4x=12\\\\\frac{4x}{4}=\frac{12}{4}\\\\x=3$

x = 3