Question

a+b+c+d=120
d=c:2
c=b:3
a=d+10

a=?,b=?,c=?

Answer 1

d=c:2
b=3 x c
a= c:2 +10
a+b+c+d = (c:2+10) + 3 x c + c + c:2 = 120
(c+20)/2 + (2 x (3 x c) )/2 + (2 x c) / 2 + c/2 = 240/2
se simplifica numitorul => c+20 + 6 x c +2 x c + c =240
10 x c= 240-20
10 x c = 220
c= 220:10 = 22
d=c:2=22:2=11
a=c:2+10=22:2+10=11+10=21
b=3 x c=3 x 22= 66

Answer 2

a+b+c+d= 120
daca c=b:3 => b=3c
daca d=c:2=> c=2d
d+10+3c+2d+d = 120
4d +3c +10 =120
4d+3c=110
4d+3x2d=110
4d+ 6d = 110
10d=110
d= 110:10
d=11
a=11 + 10
a =21 
c=11x2
c=22
b=22x3
b=66