math(要例式)快快快,有10分

sophia= x

dick=x+28

gary=x/4

maria=18+x/4=28

x=40

dick = 38

let G be age of gary, M be age of maria, D is age of dick, S is age of sophia

S+28=D
G=S/4
M=G+18

when maria is 28
M=28=G+18
G=28-18
G=10

G=10=S/4
S=10*4
S=40

S+28=D
40+28=D
D=68

therefore dick is 68 years old.

Let x be the age of dick
(x-28)/4+18=28
(x-28)/4=10
x-28=40
x=68
The age of dick is 68.

Let the age of Dick be a years old
Let the age of Sophia be b years old
Let the age of Gary be c years old
a = b + 28
c = ¼ b
c = 28 - 18 = 10
10 = ¼ b
40 = b
a = b + 28 = 40 + 28 = 68
Ans. Dick is 68 years old.