Question

How do you solve `7x + 30=51`?

Answer 1

`x=3`

Explanation:

Take away the constant…

`7x+cancel30-cancel30=51-30`

`7x=21`

Divide by `7` to find `x`:

`x=21/7=3`

You can check by using the equation:

`(7xx3)+30=21+30=51` which is correct.

Answer 2

`x=3`

Explanation:

`"isolate 7x by subtracting 30 from both sides of the "`
`"equation"`

`7xcancel(+30)cancel(-30)=51-30`

`rArr7x=21`

`"divide both sides by 7"`

`(cancel(7) x)/cancel(7)=21/7`

`rArrx=3" is the solution"`

`color(blue)"As a check"`

`(7xx3)+30=21+30=51="right side"`