Question

Solve the system of equations by either the addition method or the substitution method.



Choose one answer.
a. (4, 1)
b. (1, 4)
c. infinite number of solutions
d. no solution

Answer 1

2x + -y = 7
2x - 2y = 6

I would use gauss-jordan elimination.

2 -1 7
2 -2 6

2 -1 7
1 -1 3

1 -1 3
0 1 1

1 0 4
0 1 1

x = 4, y = 1

Answer 2

a. (4, 1)