Question

try to answer this question ( four years later....)

Answer 1

x+4=3(y+4)x-3y=12-4x-3y=8

Answer 2

here taking father's present age =x years
and his son's present age = y

a/c to question ,

x+4 = 3(y +4)

x -3y = 12 -4

x -3y = 8 , this is linear equation of two variables . graph given above pic .

again,

if his son's age 10years

then, father's age = 3y + 8
=3(10) + 8 = 38 years