Question

1. Las ecuaciones de incógnita “x”
a) 3x + 2 = x - 5
b) 3x + 2x – 9 = 4x + 11
c) 8x – 7 = x – 7 + 4x - 10
d) 11x + 5x – 1 = -36 + 65 x

Answer 1

a)

$3x+2=x-5\\3x+2-2=x-5-2\\3x=x-7\\3x-x=x-7-x\\2x=-7\\\frac{2x}{2}=\frac{-7}{2}$

$x=-\frac{7}{2}$

b)

$3x+2x-9=4x+11\\5x-9=4x+11\\5x-9+9=4x+11+9\\5x=4x+20\\5x-4x=4x+20-4x\\x=20$

c)

$8x-7=x-7+4x-10\\8x-7+7=x-7+4x-10+7\\8x=x+4x-10\\8x=5x-10\\8x-5x=5x-10-5x\\3x=-10\\\frac{3x}{3}=\frac{-10}{3}$

$x=-\frac{10}{3}$

d)

$11x+5x-1=-36+65x\\16x-1=-36+65x\\16x-1+1=-36+65x+1\\16x=65x-35\\16x-65x=65x-35-65x\\-49x=-35\\\frac{-49x}{-49}=\frac{-35}{-49}$

$x=\frac{5}{7}$