Question

Which point in not on the line y=10-2x
(1,10)
(5,0)
(10,-10)

Answer 1

(5,0) and (10,-10) is on the line and (5,0) is not so the answer is (5,0)

Answer 2

substitute the values of x and y into the equation

(1,10)    10 = 10 - 2(1)
              10 = 8                      (this is not on the line of equation y = 10 - 2x)

(5,0)      0 = 10 - 2(5)
             0 = 0

(10,-10)    -10 = 10 - 2(10)
                 -10 = -10