Question

If x:y = 3:4, then (7x+3x) : (7x-3y) =?

Answer 1

Your question needs a correction.

Correct question : If x:y = 3:4, then (7x+3y) : (7x-3y) =?

Answer:

Value of $\dfrac{7x+3y}{7x-3y}\:\:is\:\:11 : 3$

Step-by-step explanation:

It is given that the ratio of x and y is 3 : 4.

To find : $\dfrac{7x+3y}{7x-3y}$

Divide both numerator and denominator by y,

$\implies \dfrac{\dfrac{7x+3y}{y}}{ \dfrac{7x-3y}{y}}\\\\\\\implies \dfrac{\bigg( 7 \times \dfrac{x}{y} \bigg) + \bigg( 3 \times \dfrac{y}{y}\bigg)}{\bigg( 7 \times \dfrac{x}{y} \bigg) - \bigg( 3 \times \dfrac{y}{y}\bigg)}\\\\\\\implies \dfrac{\bigg( 7 \times \dfrac{x}{y} \bigg) + 3}{\bigg( 7 \times \dfrac{x}{y} \bigg) -3}$

Substituting the value of x : y,

$\implies \dfrac{\bigg( 7 \times \dfrac{3}{4} \bigg)+3}{\bigg( 7 times \dfrac{3}{4} \bigg) - 3 }\\\\\\\implies \dfrac{\dfrac{21+12}{4}}{\dfrac{21-12}{4}}\\\\\\\implies \dfrac{33}{9}\\\\\\\implies \dfrac{11}{3}$

Hence,

Ratio of ( 7x + 3y ) and ( 7x - 3y ) in numbers is 11 : 3 .