x + y + z = 40x = y + 5x = 2z We can rewrite the variable information so that we can replace those with x instead:x - 5 = yx/2 = z Now that we have isolated the variables, we can put them into the equation:x + x - 5 + .5x = 40 (.5 = 1/2)2.5x - 5 = 402.5x = 45x = 18 Now that we know x, we can solve for the other variables:y = 18 - 5y = 13z = 18/2z = 9 Now to check:18 + 13 + 9 = 4018 + 22 = 4040 = 40