Pomogite pojaluysta.(81-x):5=12....(c-24)*6=78

Question

Pomogite pojaluysta.(81-x):5=12....(c-24)*6=78

Answer 1

81-x=12*5 

81-x=60
x=81-60
x=21

Answer 2

(с-24)*6=78|:6
с-24=13
с=37