[(3 + a:2):11 + 7] × 5 - 8 = 41
{[(3×2 + a)/2]:11 + 7} × 5 - 8 = 41
{[(6 + a)/2]:11 + 7} × 5 - 8 = 41
[(6 +a)/2 × 1/11 +7] × 5 - 8 = 41
[(6 + a)/22 +7] × 5 - 8 = 41
{[(6 + a) +7×22]/22} × 5 - 8 = 41
[(6 + a + 154)/22]× 5 - 8 = 41
(160 + a )/22]× 5 - 8 = 41
(5×160 + 5×a)/22 = 41 + 8
(5×160 + 5×a)/22 = 49
(5×160 + 5×a)=49 ×22
5a =49 ×22 - 5×160
5a = 1078 - 800
5a = 278
a = 55.6