Question

3) If x : y =4:7, find [4x + 5y] [5x +3y]




plz answer this question in detail ​

Answer 1

Answer:

51/41

Step-by-step explanation:

=> x/y = 4/7 → x = (4y/7)

Thus, 4x = 4(4y/7) = 16y/7

5x = 5(4y/7) = 20y/7

Hence,

4x + 5y = 16y/7 + 5y

= 51y/7

5x + 3y = 20y/7 + 3y

= 41y/7

Therefore,

(4x + 5y)/(5x + 3y) = (51y/7)/(41y/7)

= 51/41

Answer 2

Given :

• x: y= 4:7

━━━━━━━━━━━━━━━━━━━━

Need to Find:

• $\dfrac{4x + 5y}{5x + 3y} =$

━━━━━━━━━━━━━━━━━━━━

Solution:

$\dfrac{x}{y} = \dfrac{4}{7}$

$\implies \: 7x = 4y$

$\purple{\bold{ \implies \: y= \dfrac{7x}{4} }}$

Now substituting it in given equation we get,

$\dfrac{4x + 5y}{5x + 3y}$

$= \dfrac{4x +3 \times \dfrac{7x}{4} }{5x + 3 \times \dfrac{7x}{4} }$

$= \dfrac{4x + \dfrac{35x}{4} }{5x + \dfrac{21x}{4} }$

$= \dfrac{16x + 35x}{4} \times \dfrac{4}{20x + 21x}$

$\red{\bold{\large{\boxed{ = \dfrac{51}{41} (Ans)}}}}$