If x:y=3:4 then (7x+3y): (7x-3y) is equal to:Options37 : 194 : 35 : 211 : 3

The given ratio is x:y = 3:4.

We are asked to find the ratio (7x+3y) : (7x-3y).

Let's substitute x = 3k and y = 4k (where k is a constant) into the equation.

So, (7x+3y) : (7x-3y) becomes (73k + 34k) : (73k - 34k).

This simplifies to (21k + 12k) : (21k - 12k), which is 33k : 9k.

The k's cancel out, leaving us with the ratio 33:9.

This ratio can be simplified by dividing both numbers by their greatest common divisor, which is 3.

So, the simplified ratio is 11:3.

Therefore, the answer is 11:3.