Question

Calcule o valor de x nas seguintes equações:
a) 2x – 3 = 7
b) x + 7 = 19
c) 3x - 15 = 30
d) 5x + 8 = 3x + 32
e) 6x + 8 = –10
f) 2x + 9 = –1
g) 3x = 12 + x
h) 9x - 16 = 18 + 7x
i) 35x = –105
j) 7x – 1 = 13
k) 6x – 10 = 2x + 14
l) 6x = 2x + 28
m) 3(x + 2) = 15
n) 2(x – 1) – 7 = 16
o) 7(x – 2) = 5(x + 3)
p) 2(x – 6) = –3(5 + x)

Answer 1

Explicação passo-a-passo:

A)

$2x - 3 = 7$

$2x = 7 + 3$

$2x = 10$

$x = \frac{10}{2} x = 5$

B)

$x + 7 = 19$

$x = 19 - 7$

$x = 12$

C)

$3x - 15 = 30$

$3x = 30+ 15$

$x = \frac{45}{3} \\ x = 15$

D)

$5x + 8 = 3x + 32 \\ 5x - 3x = 32 - 8 \\ 2x = 24 \\ x = \frac{24}{2} \\ x = 12$

E)

$6x + 8= - 10 \\ 6x = - 10 - 8 \\ 6x = - 18 \\ x = \frac{ - 18}{6} \\ x = - 3$

F)

$2x + 9 = - 1 \\ 2x = - 1 - 9 \\ x = - \frac{ - 10}{2} \\ x = - 5$

G)

$3x = 12 + x \\ 3x - x = 12 \\ 2x = 12 \\ x = \frac{12}{2 } \\ x = 6$

H)

$9x - 16 = 18 + 7x \\ 9x - 7x = 18 + 16 \\ 2x = 34 \\ x = \frac{34}{2} \\ x = 17$

I)

$35x = - 105 \\ x = \frac{105}{35} \\ x = 3$

J)

$7x - 1 = 13 \\ 7x = 13 + 1 \\ 7x + 14 \\ x = \frac{14}{7} \\ x = 2$

K)

$6x - 10 = 2x + 14 \\ 6x - 2x = 14 + 10 \\ 4x = 24 \\ x = \frac{24}{4} \\ x = 6$

ESSA E A ( M ) EU INVERTI

$3(x + 2) = 15 \\ 3x + 6 = 15 \\ 3x = 15 - 6 \\ 3x = 9 \\ x = \frac{9}{3} \\ x = 3$

ESSA E A (L)

$6x = 2x + 28 \\ 6x - 2x = 28 \\ 4x = 28 \\ x = \frac{28}{4} \\ x = 7$

N)

$2(x - 1) - 7 = 16 \\ 2x - 2 - 7 = 16 \\ 2x = 15 - 9 \\ 2x = 6 \\ x = \frac{6}{2} \\ x = 3$

O)

$7(x - 2) = 5(x + 3) \\ 7x - 14 = 5x + 15 \\ 7x - 5x = 15 - 14 \\ 2x = 1 \\ x = \frac{2}{1}$

P)

$2(x - 6) = - 3(5 + x) \\ 2x - 12 = - 15 - 3x \\ 2x + 3x = - 15 + 12 \\ 5x = - 3 \\ x = \frac{ - 3}{ 5}$