Finding the values of x and y?

Question

The sum of John and Kevin's age is 74. In three years, John will be three times as old as kevin. How old are John and Kevin now?

Answer 1

J=John now

K = Kevin now

J+3= John in 3 years

K+3 = Kevin in 3 years

J+K=74

J+3=3(K+3); J+3=3K+9; J=3k+6; substitute

J+K=74

3k+6 + K = 74

4k = 68

K = 17

J = 57

Answer 2

Let x be the age of John.

Ley y be the age of Kevin.

x +  y = 74   (1)

(x+3) = (y + 3)*3

x + 3 = 3y + 9

x = 3y + 6    (2)

use substitution for (1) and (2),

3y + 6 + y  = 74

4y = 68

y = 17

x =  57

Therefore, John is 57 and Kevin is 17.

--Hope this helped!

Answer 3

J + K = 74

J + 3 = 3 * (K + 3)

K = (J + 3)/3 - 3

J + (J + 3)/3 - 3 = 74

J = 57

K = 17

Answer 4

if john age =x, kevin's age = y

then x+y=74

john age is 3 times for kevin

so kevin is yelder

so x= 3y here

substitute x value in first equation

then   3y+y= 74

4y=74

y=74/4 = 18.5  

kewin's age = 18.5 years

johns age = 74-18.5 = 55.5 years

goodluck