Thread: Having trouble solving this equation

1. Having trouble solving this equation

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?

2. Originally Posted by Layman
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?
Dear Layman,

This one is also similar to the above problem. Substract 45 from both sides, then divide both sides by -5.

3. 45-50=5x
-5=5x
therefore, x= -1

4. Thanks.....so is it as follows?

45 - 5x = 50

45 - 45 - 5x = 50 - 45
-5x = 5
-5x/5 = 5/1
x = -1

5. absolutely right