we just simply substitute the values of the points given so as to obtain the missing coordinates
@ (x, 14)
y = 0.5x +12
14 = 0.5x +12
x = 4
therefore the point is at (4, 14)
@ (18, y)
y = 0.5x + 12
y = 0.5*(18) +12
y = 21
therefore the point is at (18, 21)