Question

1. Solve the system of equations using the linear combination method.

Answer 1

The linear combination method involves multiplying, adding and subtracting in such a way that allows one variable to be eliminated in the addition or subtraction step. This leaves the other variable alone, allowing its value to be determined.

1. 5m+3n=41, 3m−6n=9
Multiply 1st equation by 2: 10m + 6n = 82
Add to 2nd equation: 13m = 91
Divide by 13: m = 7
Substitute back to 1st equation: n = 2
Therefore m = 7 and n = 2.

2. 6g+8h=40 −6g+2h=−20
Add both equations: 10h = 20
Divide by 10: h = 2
Substitute to 1st equation: g = 4
Therefore g = 4 and h = 2.

3. 9x+5y=35 2x+5y=0
Subtract 1st equation by the 2nd equation: 7x = 35
Divide by 7: x = 5
Substitute back to the 1st equation: y = -2
Therefore x = 5 and y = -2.