How do you solve for x: 6(x+1)=12(x-3)?

2 Answers
Feb 4, 2017

See the entire solution process below:

Explanation:

First, expand all the terms in exponents:

(6 xx x) + (6 xx 1) = (12 xx x) - (12 xx 3)

6x + 6 = 12x - 36

Next, subtract color(red)(6x) and add color(blue)(36) to each side of the equation to isolate the x term while keeping the equation balanced:

6x + 6 - color(red)(6x) + color(blue)(36) = 12x - 36 - color(red)(6x) + color(blue)(36)

6x - color(red)(6x) + 6 + color(blue)(36) = 12x - color(red)(6x) - 36 + color(blue)(36)

0 + 42 = 6x - 0

42 = 6x

Now, divide each side of the equation by color(red)(6) to solve for x while keeping the equation balanced:

42/color(red)(6) = (6x)/color(red)(6)

7 = (color(red)(cancel(color(black)(6)))x)/cancel(color(red)(6))

7 = x

x = 7

Feb 4, 2017

x=7

Explanation:

6(x+1)=12(x-3)

:.6x+6=12x-36

:.6x-12x=-36-6

:.-6x=-42

multiply both sides by -1

:.6x=42

:.x=cancel42^7/cancel6^1

:.x=7

substitute x=7

:.6(7+1)=12(7-3)

:.6 xx 8=12 xx 4

:.48=48