Question

"4+[9-(8+a*6)/10]*5=39"

Answer 1

4 + [9 - (8 + a x 6) : 10] x 5 = 39
[9 - (8 + a x 6) : 10] x 5 = 39 - 4
[9 - (8 + a x 6) : 10] x 5 = 35
9 - (8 + a x 6) : 10 = 35 : 5
9 - (8 + a x 6) : 10 = 7
(8 + a x 6) : 10 = 9 - 7
(8 + a x 6) : 10 = 2
8 + a x 6 = 2 x 10
8 + a x 6 = 20
a x 6 = 20 - 8
a x 6 = 12
a = 12 : 6
a = 2

Answer 2

4+[9-(8+ax6)/10]x5=39
[9-(8+ax6)/10]x5=39-4=35
9-(8+ax6)/10=35:5=7
8+ax6/10=9-7=2
(8+ax6):10=2
8+6xa=2x10=20
6xa=20-8=12
a=12:6=2