Question

Given: 3x - 4 = 2(x + 8), Prove: x = 20

Answer 1

x = 20

Explanation:

The goal is to move the x's and the whole numbers to their own sides of the equation. When moving pieces to opposite sides, the signs change (a negative becomes a positive, for example).

3x - 4 = 2(x + 8)

First we're going to use distributive property to remove the brackets in

2(x + 8)

This becomes 2x + 16

3x - 4 = 2x + 16

Moving 2x over...

3x - 2x - 4 = 16

Moving -4 over...

3x - 2x = 16 + 4

Collecting like terms...

x = 20

Answer 2

For this case we have the following expression:

`3x-4 = 2 (x + 8)`

We must prove in the equation
`x = 20`

We apply distributive property on the right side of the equation:

`3x-4 = 2x + 16`

We subtract 2x on both sides:

`3x-2x-4 = 16`

We add 4 to both sides:

`x = 16 + 4\\x = 20`

ANswer:

`x = 20`