Question 971828
y = [(2*(x+10) - 18) * (1/2)] - x 
now we have y = 1 and we are asked to solve for x
1 = [(2*(x+10) - 18) * (1/2)] - x
1 = (2x + 20 - 18) * (1/2) - x
1 = x + 1 - x
1 = 1
therefore any number that is picked will yield a result of 1