Solving systems of equations Quiz

1) A student uses the substitution method to solve the system of equations below algebraically.

2x – y = 5
3x + 2y = -3

Which equation could be used?

a. 3x + 2(2x – 5) = -3

b. 3x + 2(5 – 2x) = -3

c. 3(y + 5/2) + 2y = -3

d. 3(5/2 – y) + 2y = -3

2) Which linear system has been correctly solved for one of the variables from the following system?

2x – y = -1
2x + y = -7

2 x space minus space y space equals space minus 1 space_x000D_
y space equals space 2 x space minus space 7

y space equals space 2 x space plus space 1 space_x000D_
2 x space plus space y space equals space minus 7

3) Which linear system has the solution (6, 6)?

3 x space plus space y space equals space 4_x000D_
4 x space minus space 3 y space equals space 1

4 x space minus space 3 y space equals space minus 1 space space_x000D_
minus 2 x space plus space y space equals space minus 3

4) A student is using the elimination method to solve the system of equations below. What is the best first step?

3x – y = 5
2x + 3y = 10

a. Multiply the second equation by 3.

b. Multiply the first equation by 3.

c. Multiply the second equation by 2.

d. Multiply the first equation by 2.

5) In which line is a mistake first made when solving the following system of equations by elimination for s?

2r + 7s = 11
r – 9s = -7

Line 1 2r + 7s = 11
2(r – 9s = -7)
Line 2 2r + 7s = 11
2r – 18s = -14
Line 3 -11s = -3
Line 4 s = 11/3

a. Line 1

b. Line 2

c. Line 3

d. Line 4

6) Find the solution to the system of equations.

4c = 3d + 3
c = d – 1

a. c = 6, d = 7

b. c = 3, d = 4

c. c = 8, d = 7

d. c = 5, d = 4

7) What is the solution to the system of equations.

2x – 3y = -9
-x + 3y = 6

a. (3, 3)

b. (-3, 1)

c. (-3, 3)

d. (1, -3)