Question

68-4×[1150-6 × ( 40 × a -25)÷ 3 ] ÷ 10 = 20
Cat este a?

Answer 1

68 - 4 x [1150 - 6 x (40 x a - 25) : 3] : 10 = 20
4 x [1150 - 6 x (40 x a - 25) : 3] : 10 = 68 - 20
4 x [1150 - 6 x (40 x a - 25) : 3] : 10 = 48
[1150 - 6 x (40 x a - 25) : 3] : 10 = 48 : 4
[1150 - 6 x (40 x a - 25) : 3] : 10 = 12
1150 - 6 x (40 x a - 25) : 3 = 12 x 10
1150 - 6 x (40 x a - 25) : 3 = 120
6 x (40 x a - 25) : 3 = 1150 - 120
6 x (40 x a - 25) : 3 = 1030
6 x (40 x a - 25) = 1030 x 3
6 x (40 x a - 25) = 3090
40 x a - 25 = 3090 : 6
40 x a - 25 = 515
40 x a = 515 + 25
40 x a = 540
a = 540 : 40
a = 27 : 2
a = $\frac{27}{2}$