How does x=3?
Simple. 5x-7=8 is the equation displayed.
We add 7 to both sides so we can try to cancel as many things as possible. 5x-7+7=8+7 ===>15.
We now have to cancel that 15 to get x. We do the opposite of multiplying by 5 (seen when 5 and x are together) we divide by 5 to both sides ====> 5x/5=15/5 ======> x=3. Thus, x is equal to 15!
Hope this helps!!!