7x+1y = 17.00 can be simplified to y = -7x +17 <span>-7x +17 can then be substituted for y in 3x+ 4y =17.50 </span>3x+4(y) = 17.50 3x+ 4(-7x +17) = 17.50
From here you can solve for X <span>3x + 4(-7x +17) = 17.50 </span>3x -28x + 68 = 17.50 -25x + 68 = 17.50 -68 -68 -25x = -50.50 ÷-25 ÷-25 X = 2.02
You can then replace x with 2.02 in the original 7x + 1y = 17.00 to solve for y.
7(x) + 1y = 17.00 7(2.02) + y = 17.00 14.14 + y = 17.00 -14.14 -14.14 y = 2.86
Then substitute 2.02 for x and 2.86 for y in the original 3x+ 4y = 17.50 to check. 3(x) + 4(y) = 17.50 3(2.02) + 4(2.86) = 17.50 6.06 + 11.44 = 17.50 17.50 = 17.50 So X = 2.02 and Y = 2.86 or the solution set is (2.02, 2.86)
