Réponse :

Bonsoir

1- Mike’s mother age: 4*x = 4x

Mike’s sister age: x-6

2- x is the age of Mike, so:

x + 4x + x-6 = 48

3a- solve the equation to find mike’s age:

x+4x+x-6 = 48

6x-6 = 48

6x=48+6

6x = 54

x = 54/6

x = 9

Mike is 9 years old.

b- When Mike was born, his mother was 27

(because: now she is 4*9 = 36 years old, 9 years ago, she had 36-9 = 27 years old).