John is 4 times as old as Mary. The sum of their ages 6 years from now will be 3 more than 6 times John present age. The age of John is
Plzzzz answer fast I have exam tomorrow
Answers
Answered by
0
Let the age of Mary be x
And the age of John be y
According to question, y=4x or 4x-y=0 (1)
After 6 years
Age of Mary = 6+x
Age of John = 6+y
Sum of ages = (x+6)+(y+6) = 6y+3
x+6+y+6 =6y+3
x-5y=3-12
x-5y=-9 (2)
Using elimination method multiply equation (1) by 5
20x-5y=0
x-5y=-9
Subtracting
19x=9
x=9/19
put x in (1) equation
4(9/19)-y=0
y=36/19
And the age of John be y
According to question, y=4x or 4x-y=0 (1)
After 6 years
Age of Mary = 6+x
Age of John = 6+y
Sum of ages = (x+6)+(y+6) = 6y+3
x+6+y+6 =6y+3
x-5y=3-12
x-5y=-9 (2)
Using elimination method multiply equation (1) by 5
20x-5y=0
x-5y=-9
Subtracting
19x=9
x=9/19
put x in (1) equation
4(9/19)-y=0
y=36/19
Similar questions