Question

a soma de dois numeros e 48 e a razao entre eles e sete quintos

Answer 1

x + y = 48   -----> x = 48 - y

x/y = 7/5

(48-y)/y = 7/5

7y = 240 - 5y

12 y = 240   -------> y = 20

x + 20 = 48   -----> x = 28

Answer 2

x+y=48   ===> x=48-y  ===> x = 48-20 = 28
x/y=7/5                                        
                                                        x=28
Substituindo                                      y=20
5 . (48-y) = 7y
240 - 5y = 7y
-5y -7y = - 240
-12y= -240
y= 20