Solve the system of equations

3x+6y=21
-5x+2y=13

1 answer

To solve the system of equations:

3x + 6y = 21 (equation 1)
-5x + 2y = 13 (equation 2)

We can use the method of substitution or elimination. Let's solve it using substitution:

1. Solve equation 1 for x:
3x = 21 - 6y
x = (21 - 6y) / 3
x = 7 - 2y (equation 3)

2. Substitute equation 3 into equation 2:
-5(7 - 2y) + 2y = 13

Distribute -5:
-35 + 10y + 2y = 13

Combine like terms:
12y - 35 = 13

Add 35 to both sides:
12y = 13 + 35
12y = 48

Divide by 12:
y = 48/12
y = 4

3. Substitute y = 4 into equation 3 to find x:
x = 7 - 2(4)
x = 7 - 8
x = -1

Therefore, the solution to the system of equations is x = -1 and y = 4.