Question

If `7x +5 = -2`, what is the value of `8x`?

Answer 1

See a solution process below:

Explanation:

First, solve the equation for `x`:

`7x + 5 = -2`

`7x + 5 - color(red)(5) = -2 - color(red)(5)`

`7x + 0 = -7`

`7x = -7`

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

`(color(red)(cancel(color(black)(7)))x)/cancel(color(red)(7)) = -1`

`x = -1`

Now, substitute `color(red)(-1)` for `color(red)(x)` in the expression and calculate the value of `8x`

`8color(red)(x)` becomes:

`8 * color(red)(-1) => -8`