Answer:
Below in bold.
Explanation:
Let x be George's age and y be Genemy's age.
x/y = 5/7
(x + 4)/ (y + 4) = 3/4
From equation 1, y = 7x/5 = 1.4x so substituting in equation 2 :
(x + 4)/ (1.4x + 4) = 3/4
3(1.4x + 4) = 4(x + 4)
4.2x + 12 = 4x + 16
0.2x = 16 -12 = 4
x = 4/0.2 = 20 = George's age.
So y = 1.4x = 1.4 * 20 = 28 = Genemy's age.