Question

40+90:[9+48:(a+6)]=46

Answer 1

40+90:[9+48:(a+6)]=46
90:[9+48:(a+6)]=46 - 40
90:[9+48:(a+6)]=6
9+48:(a+6)= 90 :6
9+48:(a+6) = 15 
48:(a+6) = 15 - 9
48:(a+6) = 6
a+6=48:6
a+6=8
a=8-6
a=2 

Answer 2

40+90:(9+ 48/a+6)=46
40+90: 9(a+6)+49/a+6=46
40+90:9a+ 54+48/a+6=48
40+90: 9a+102/a+6
40+90(ori) a+6/9a+102
40+ 30(a+6)/3a+34
30a+180/3a+34
30a+108=6(3a+34)
30a-18a=204-108
12a=24
24/12=2 ..... deci a =2