Question 660868
x = one number
y = another number
x = 4 + y
so x is the greater number
3x = 4y

Multiply the first equation by -3 and add the second equation
-3(x = 4+y)
-3x = -12 - 3y

-3x + 3x = 4y + -3y + -12
0 = y - 12
12 = y

x = 4 + 12 = 16
Proof
3(16) =48 
4(12) =48

Alternatively, solve by simple substitution as
3(4+y) = 4y
12 + 3y = 4y
12 = 4y - 3y
12=y