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Mary's age is twice the sum of John's age and 3. The sum of both ages is 21 years. Find the age of each one.

Respuesta :

m = 2(j + 3)

m + j = 21

m = 21 - j

equating  first and third equations:-

2(j + 3) = 21 - j

2j + j = 21 - 6

3j =  15

j = 5

so m = 21 - 5 = 16

So Johns age  is 5 and Mary's age is  16  answer