Question

encontrar el valor de x :
a) 2 x = 5 + x
b) 2 x + 18 = x +21
c) 2(x+7)= 9 x
d) 3 x -7= x +29

Answer 1

Respuesta:

a)

$2x = 5 + x \\ 2x - x = 5 \\ x = 5$

b)

$2x + 18 = x + 21 \\ 2x - x = 21 - 18 \\ x = 3$

c)

$2(x + 7) = 9x \\ 2x + 14 = 9x \\ 14 = 9x - 2x \\ 14 = 7x \\ x = \frac{14}{7} \\ x = 2$

d)

$3x - 7 = x + 29 \\ 3x - x = 29 + 7 \\ 2x = 36 \\ x = \frac{36}{2} \\ x = 18$