Download Math 123 Chapter 4 Review Worksheet For extra credit, turn in your

Math 123 Chapter 4 Review Worksheet
For extra credit, turn in your solutions fully worked out on separate paper. Don’t try to squeeze in your
solutions on this worksheet. Answers are at the end, so obviously there will be no credit for just turning in the
answers!
Solve the systems of equations below. If there is no solution, or if there are infinitely many solutions, say so.
1.
2x – y = 6
3x – 5y = 16
8.
x = 0.1y – 6.9
y = –1.9x – 2.4
16.
–6x – 2y = 22
–7x + 4y = 32
2.
y = –3x – 4
y = 2x + 1
9.
x
5
7
y
4
4
9
3
y  x
4
2
17.
4x + 3y = –11
–3x – 8y = –9
18.
5x = –9y – 21
–5y = 4x + 19
3.
4.
5.
6.
7.
1
y  x4
3
2
y  x5
3
3
x 1
2
3x = 2y – 3
y
2x = 6 – 3y
2
y  x2
3
y = –3x + 20
6x – 6y = –24
x – 3y = 9
3x + y = –23
10.
y = 500x – 3160
y = –350x + 2790
19.
–5.9x + 4.1y = 5.4
0.1x – 8.7y = 25.8
11.
3(x – 2y) = –18
9x = –8y – 2
20.
–3(x + y) = 6 – 7y
7(x – 2y) = –14 – 5y
12.
–4x + 8y = 4
x = 2y – 1
13.
14.
15.
1
y   x 3
9
x + 9y = 5
3x + 4y = 10
–3x – 5y = –14
–9x – 4y = 16
2x + 4y = –16
21.
1
1
33
x y 
5
4
10
7
7
7
 x y 
6
6
2
22.
3x + 5y = 61
–12x – 20y = –244
23.
–4x + 14y = 58
–0.2x = 2.3 – 0.7y
24.
A theater group sells adult tickets for $13 each, and sells children’s tickets for $8 each. If they sell a total
of 70 tickets for $705, how many adult tickets and how many children’s tickets do they sell?
25.
If 6 hot dogs and 5 drinks cost $25.10, and if 5 hot dogs and 3 drinks cost $18.00, what is the cost of one
hot dog and what is the cost of one drink?
26.
A chemist wants to mix a solution that’s 22% acid with a solution that’s 46% acid to get 32 liters of a
solution that’s 37% acid. How many liters of the 22% solution and the 46% solution should be mixed?
27.
Pure acetone is mixed with a solution that’s 40% acetone to make 30 ounces of a solution that’s 58%
acetone. How many ounces of pure acetone and how many ounces of the 40% solution are needed?
28.
A barge takes 1 hour to travel 7 miles with the current, and takes 7 hours to return against the current.
Find the speed of the barge in still water and the speed of the current.
29.
A plane flew 800 miles in 4 hours with the wind. It took 5 hours to travel the same distance against the
wind. Find the speed of the plane in still air and the speed of the wind.
Answers:
1. x = 2, y = –2
2. x = –1, y = –1
3. x = –3, y = 1
4. No solution
5. Infinitely many solutions
6. x = 4, y = 8
7. x = –6, y = –5
8. x = –6, y = 9
9. x = 2, y = –3
10. x = 7, y = 340
11. x = –2, y = 2
12. Infinitely many solutions
13. No solution
14. x = –2, y = 4
15. x = 0, y = –4
16. x = –4, y = 1
17. x = –5, y = 3
18. x = –6, y = 1
19. x = –3, y = –3
20. x = –2, y = 0
21. x = –9, y = –6
22. Infinitely many solutions
23. No solution
24. 29 adult tickets, 41 children’s tickets
25. $2.10 for one hot dog, $2.50 for one drink
26. 12 liters of the 22% solution, 20 liters of the 46% solution
27. 9 ounces of pure acetone, 21 ounces of the 40% solution
28. Barge in still water: 4 miles per hour; current: 3 miles per hour
29. Plane in still air: 180 miles per hour; wind: 20 miles per hour