18 x 3 + 12 - 1 x 34 + 13 - 2 x 56 = 67
<=Work=>
18 x 3 = 54
1 x 34 = 34
2 x 56 = 112
(54) + 12 - (34) + 13 - (112)
66 - 34 + 13 - 112
32 + 13 - 112
45 - 112
= 67
Just substitute x = 2 and y = 5 into the equation wherever you see x and y.
2 + (12 - 5x) · 2y
2 + (12 - 5(2)) · 2(5)
2 + (2) · 10
4 · 10
40, is the answer which should be the first box.