Amother is currently 7 times older than her son. in 3 years time, she will be 5 times older than her son. let x and y be the present ages of the son and mother respectively.

Mother's present age: 42

Son's present age: 7

Step-by-step explanation:

Let x represent the mother's age

Let y represent the son's age

The mother is currently seven times (×7) older than her son i.e.

x = 7 × y

x = 7y (eqn 1)

In three years time i.e. the mother and son's age plus three (3)

x + 3 and y + 3

The mother will be 5 times (×5) older i.e.

x + 3 = 5 × (y + 3)

x + 3 = 5(y + 3)

x + 3 = 5y + 15

Collect like terms

x = 5y + 12 (eqn 2)

Since x = 7y in eqn 1, we substitute x in eqn 2 i.e.

7y = 5y + 12

7y - 5y = 12

2y = 12

y = 6

Since y=6, we substitute 6 in eqn 1

x = 7y

x = 7 × 6

x = 42

Hence, the present age of the mother and her son are 42 and 6 respectively.

answer: i don't understand it

step-by-step explanation: sorry

17

step-by-step explanation:

51/3=17

thus 17 is your answer.