Let's say for example I have;

7x + 8 = 71 I don't have a problem solving this, I can do it as follows;

7x + 8 - 8 = 71 - 8

7x = 63

7x/7 = 63/7

x = 9

The above was done, as you can see by using the addition/subtraction rule and then the division rule.

However, the follwing equation stumps me;

45 - 5x = 50

Can someone enlighten me?