Question

Solve the systems of equations 6x+3y=9 2x+3y=1

Answer 1

Solve by elimination.
The goal is to cancel out one of the variables in order to easily solve for the other variable.

Do this by changing the equations so that the coefficients of either x or y add up to 0.

Notice the coefficients of y are 3 and 3, if we make one of them negative then they add up to 0. 3+ (-3) = 0

Multiply 2nd equation by -1.

6x +3y = 9
-2x -3y = -1
__________
4x +0y = 8

Solve for x
4x = 8
x = 8/4 = 2

Plug x=2 back into one of original equations to find y.
---> 2(2) + 3y = 1
---> 4 + 3y = 1
---> 3y = -3
---> y = -1

Therefore solution is (2,-1)