The third proportional to x2-y2 and x-y is :

Q: The third proportional to x2-y2 and x-y is :

Let the third proportional to x 2 - y 2 and x - y be z. Then, x 2 - y 2 : x - y : : x - y : z = > x 2 - y 2 * z = x - y 2 => z= x - y 2 x 2 - y 2 = x - y x + y

(x + y )
(x - y)
(x + y) / ( x - y)
(x -y) / ( x + y)

Correct Answer: (x -y) / ( x + y)

Explanation:

Let the third proportional to $x 2 - y 2$ and $x - y$ be z. Then,

$x 2 - y 2 : x - y : : x - y : z$

$= > x 2 - y 2 * z = x - y 2$

=> z= $\frac{x - y}{2} = \frac{x - y}{x + y}$

More Questions from Ratio and Proportion

If 76 is divided into four parts proportional to 7, 5, 3, 4, then the smallest part is:
The wages of labourers in a factory increases in the ratio 22:25 and there was a reduction in the number of labourers in the ratio 15:11. Find the original wage bill if the present bill is Rs. 5000 ?
3 : 12 :: 5 : ?
One year ago the ratio between Maneela’s and Shanthi’s salary was 3 : 4. The ratios of their individual salaries between last year’s and this year’s salaries are 4 : 5 and 2 : 3 respectively. At present the total of their salary is Rs. 4160. The salary of Maneela, now is?
The sum of three numbers is 98. If the ratio of the first to second is 2 : 3 and that of the second to the third is 5 : 8, then the second number is:
For any two numbers m , n ; (m+n) : (m-n) : mn = 7: 1: 60 . Find the value of 1/m : 1/n
A cubical block of metal weighs 6 pounds. How much will another cube of the same metal weigh if its sides are twice as long?
Rice worth Rs. 126 per kg and Rs. 135 per kg are mixed with a third variety in the ratio 1 : 1 : 2. If the mixture is worth Rs. 153 per kg, then the price of third variety of rice per kg?
If the ratio of the ages of two friends A and B is in the ratio 3 : 5 and that of B and C is 3 : 5 and the sum of their ages is 147, then how old is B?
The ratio of the incomes of Pavan and Amar is 4 : 3 and the ratio of their expenditures are 3:2. If each person saves Rs. 1889, then find the income of Pavan?

Discussion & Comments

No comments yet. Be the first to comment!