Question

Solve the system using the addition method. Write your answer as an ordered pair. If there is no solution,write NS for your answer.4x - y = 202x + y = 22

Answer 1

Given

4x - y = 20

2x + y = 22

Using the addition method, align like variables and constant, then, add them together

4x - y = 20

+ 2x + y = 22

6x + 0y = 42

6x = 42

Divide both sides by 6, to get rid of the coefficient on the left side

6x/6 = 42/6

x = 7

Now that we have x = 7, substitute it to any of the two given equations, in this case we will use 2x + y = 22 (note: using 4x - y = 20 works just as well)

2x + y = 22

2(7) + y = 22

14 + y = 22

y = 22 - 14

y = 8

Therefore, the solution to the system is (7,8).