Question

what should be added to each term of ratio 7:9,so that the ratio becomes 5:6

Answer 1

Let x to be added.
Then,
$\frac{7 + x}{9 + x} = \frac{5}{6} \\ 6(7 + x) = 5(9 + x) \\ 42 + 6x = 45 + 5x \\ 6x - 5x = 45 - 42 \\ x = 3$

Answer 2

this is the answer i.e 3