In solving expressions, the biggest thing that you will need to pay attention to is following the steps of PEMDAS. An explanation of PEMDAS is below.
In the model problem below (7+3) - 9 x 11, although the parenthesis is in the front, it would be completed first regardless of its position in the expression. The answer is 10. You write it below the problem and bring the other expressions down with it.
The next thing you would do is solve the exponent. It is 10 to the second power (10 x 10). The answer is 100. Write the answer below and bring the rest of the expression down with it.
The next step is multiply OR divide. As you can see, 100-9 is in the front of the expression, but that is not the next step. If you are completing this expression correctly, multiplication should be completed next (9 x11). Bring the answer (99) down (along with the rest of the expression).
The final step is add or subtract. Since there is only one thing left to do, you would subtract 100-99 and get the answer of 1.
Try the following problems below. Don't forget to use PEMDAS!
4.) Multiply the difference of 19 and 11 and the quotient of 12 and 4
5.) Divide the sum of 15 and 17 and the sum of 9 and 7