## ← Practice 2 - Visualizing Algebra

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Showing Revision 2 created 05/25/2016 by Udacity Robot.

1. So, did you get 94? Because that's the correct answer. Let's review the steps,
2. and see how we got that answer. When you want to replace the variables with
3. their values, remember to use parentheses. After I substitute negative 2 in for
4. x, 2 in for y And negative 3 in for z, this is what I get 4 times negative 2 to
5. the 2nd power, negative 2 times negative 3 plus 3 times negative 2 times 2
6. squared times negative 3. Once again, we need to use order of operations to
7. evaluate this expression. First, I want to evaluate my exponents or my powers. I
8. have two exponents, I have two squared here. And I have negative 2 squared here,
9. negative 2 sqyared is negative 2 times negative 2 which is 4. Remember to copy
10. down the rest of the operations that you haven't performed whenever you're doing
11. order of operations. I also evaluated 2 squared and gave me 4. Now that there's
12. no exponents in my expression I can perform my multiplication and division in
13. order from left to right. First I have 4 times 4 which is 16. Then I have
14. negative 2 times negative 3 which is positive 6. Now I can multiply these four
15. numbers together. Feel free to get out your calculator. Now that I've performed
16. all of the multiplication and division, I can go to addition and subtraction.
17. Once again, I do everything in order from left to right. 16 plus 6 is 22 plus 72
18. gives us 94. If you're having difficulty, feel free to go back and review some
19. of the videos and try again. If you feel comfortable with the material, let's
20. move on.