Question

a+b+c=216
a=3x(b+c)
c=b+20

Answer 1

a+b+c=216
a=3x(b+c)
c=b+20

b+c=216-a
a=3x(216-a)
a=648-3a
a+3a=648
4a=648
a=648:4
a=162

162+b+b+20=216
2b+182=216
2b=216-182
2b=34
b=34:2
b=17

c=17+20
c=37

162+17+37=216

Answer 2

a+b+c=216
a=3x(b+c)
c=b+20
inlocuim....

3x (b+b+20)+b+b+20=216
3b+3b+3×20+b+b+20=216
8b+60+20=216
8b+60=216-20
8b+60=196
8b=196-60
8b=136
b=136:8
b=17

c=b+20
b=17
inlocuim....
c=17+20 》c=37

a=3x(b+c)
b=17
c=37
inlocuim....
a=3×(17+37) 》a=3×54 》a=162