adding the two equations 3x + 6y + 3x - 6y = 36+0 6x = 36 x = 6 . subtracting second equation from first (3x + 6y ) - (3x-6y) =36 -0 12y = 36 y = 3 . therefore x = 6 and y = 3 (6,3)
Short Answer A Remark These two equations have been set up so that all you have to do is add them in the first step.
Step One 3x + 6y = 36 3x - 6y = 0 Add them The 6ys will cancel out. 6x = 36
Step Two Divide by 6 6x/6 = 36/6 x = 6
Step three Use the original first equation to solve for y 3x + 6y = 36 Substitute 6 for x 3(6) + 6y = 36 18 + 6y = 36 Subtract 18 from both sides. 6y = 36 - 18 6y = 18 Divide by 6 6y/6 = 18/6 y = 3
Conclusion The solution to these two equations is (6,3)
