Ur gonna have to pick an equation and solve for a variable.
2x - 2y = 6 2x = 2y + 6 ...divide everything by 2 because u want x by itself x = y + 3
now we sub y + 3 in for x in the other equation 14x - 2y = 78 14(y + 3) - 2y = 78...distribute thru the parenthesis 14y + 42 - 2y = 78...subtract 42 from both sides, cancelling the 42 on the left -42 -42 ----------------------- 14y - 2y = 36 ...simplify 12y = 36...divide by 12 on both sides, cancelling out the 12 on the left y = 36/12 y = 3
now , we already know that x = y + 3...and we know y = 3...so sub in 3 for y and solve for x x = y + 3 x = 3 + 3 x = 6
solution is (6,3)
it is always a good idea to check ur answer by subbing it into one or both of the equations to see if it is correct 2x - 2y = 6......(6,3)...x = 6 and y = 3 2(6) - 2(3) = 6 12 - 6 = 6 6 = 6 (correct)
