Question

If x : y = 3 : 4, then find the value of (3x+4y) : (4x+7y)

Answer 1

Heya ✌✌

x:y = 3:4

Let x be 3k and y be 4k

Then,

(3x+4y) : (4x+7y) =

$\frac{3x + 4y}{4x + 7y} = \frac{3 \times 3k + 4 \times 4k}{4 \times 3k + 7 \times 4k} \\ \\ = \frac{9k + 16k}{12k + 28k} = \frac{25k}{ 40k} = \frac{5}{8}$
(3x+4y) : (4x+7y) = 5:8

Answer 2

Heya Friend ✋✋✋

$\frac{x}{y} = \frac{3}{4}$

Let x = 3a and y = 4a

$\frac{3x + 4y}{4x + 7y} \\ \\putting \: values \: of \: x \: and \: y \: \\ \\ = \frac{9a + 16a}{12a + 28a} \\ \\ = \frac{25a}{40a} \\ \\ = \frac{5}{8}$
So Ratio is 5 : 8

Hope it helps