Math problem!!!

Question

Solve the system of linear equations by elimination.

11x−20y=28

3x+4y=36

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Answer 1

11x - 20y = 28

3x + 4y = 36

----------------- (subtract the two equations)

8x - 24y = -8

Solve for 1 variable

x - 3y = -1

x = 3y - 1

Substitute for x in one of the given equations, doesn't matter which one.

11(3y - 1) - 20y = 28

33y - 11 - 20y = 28

13y = 36

y = 3

x = 3(3) - 1

x = 8

Checking

3(8) + 4(3) = 36

24 + 12 = 36

36 = 36 check!

Answer 2

11x - 20y = 28

3x + 4y = 36

multiply second equation by 5 (so when add two equations the y terms will cancel):

11x - 20y = 28

15x + 20y = 180

add two equations together:

26x = 208

x = 8

substitute 8 for x in equation 3x + 4y = 36 to solve for y:

3(8) + 4y = 36

24 + 4y = 36

4y = 12

y = 3