Question

five years hence the age of Jacob will be three times that of his son 5 years ago Jacob's as was seven times that of his son what are their present ages ​

Answer 1

Solution...

Let ,

Jocob 's age = x

Jocob son 's age = y

A.T.Q ....

Five years hence

$(x + 5) = 3(y + 5) \\ \\ x + 5 = 3y + 15 \\ \\ x - 3y = 15 - 5 \\ \\ x - 3y = 10.........(1)$

Five years ago

$(x - 5) = 7(y - 5) \\ \\ x - 5 = 7y - 35 \\ \\ x - 7y = - 35 + 5 \\ \\ x - 7y = - 30...........(2)$

By elimination method

$x - 3y = 10 \\ \frac{x - 7y = - 35}{ \frac{ - \: \: \: \: \: \: \: \: + \: \: \: \: \: \: \: \: \: \: + }{ \: \: \: \: \: \: \: \: \: 4y = 40} } \\ y = > \frac{40}{4} \\ \\ \boxed{y = > 10}$

put y value in equation (1)

$x - 3y = 10 \\ \\ x - 3(10) = 10 \\ \\ x - 30 = 10 \\ \\ x = 10 + 30 \\ \\ \boxed{x = 40}$

Jocob's age => 10

Jocob son's age = 40

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Answer 2

Answer:

Please refer the attachment dear