Answers to MTH-075 Practice Test #4

Here are the answers. Note that problems 11 and 16 have something wrong with them. Changes to make the problems solvable are suggested along with what those answers would be.

1. 9x³y⁷(4x⁵y² – 6x³ + 5y)

2. (x – y)(y + 4)

3. 4(x – 5)(x + 1)

4. (x + 7)(x – 9)

5. –x⁶(x³ + 9)

6. (3x² – 4y²)(5x + 6y)

7. (x + 12)(x – 8)

8. (5x + 2)(7x + 3)

9. (3x + 2y)(2x – 3y)

10. 5(2x – 1)(x + 6)

11. This one seems to be prime.

       It should probably read 21x² – 5x – 6.

        Then the answer would be (7x + 3)(3x – 2).

12. 2(7x² + 5y)(7x² – 5y)

13. (x – 7y)²

14. (5x + 9)²

15. (x² + 4)(x + 2)(x – 2)

16. As written, this problem can’t be solved by factoring.

       The problem should probably read 20x² + 31x + 18 = 6.

       Then the answer would be {–4/5, – ¾}.

17. {–5, –1/3, ¾}

18. {1/3, – 1/3}

19. {–8/21, –1)

20. {2, 5}