Question

How do you evaluate `2x + 5( x + 3) = 120`?

Answer 1

See a solution process below:

Explanation:

First, expand the term in parenthesis by multiplying each term within the parenthesis by the term outside the parenthesis:

`2x + color(red)(5)(x + 3) = 120`

`2x + (color(red)(5) xx x) + (color(red)(5) xx 3) = 120`

`2x + 5x + 15 = 120`

Next, we can group like terms on the left side of the equation:

`(2 + 5)x + 15 = 120`

`7x + 15 = 120`

Then, subtract `color(red)(15)` from each side of the equation to isolate the `x` term while keeping the equation balanced:

`7x + 15 - color(red)(15) = 120 - color(red)(15)`

`7x + 0 = 105`

`7x = 105`

Now, divide each side of the equation by `color(red)(7)` to solve for `x` while keeping the equation balanced:

`(7x)/color(red)(7) = 105/color(red)(7)`

`(color(red)(cancel(color(black)(7)))x)/cancel(color(red)(7)) = 15`

`x = 15`