The difference between two numbers is 14 and the difference between their squares is 448. Find the numbers.
The difference between two numbers is 14 and the difference between their squares is 448. Find the numbers.
3 Answers
Let the larger number be x and the smaller number be y.
Then, we have:
x – y = 14 or x = 14 + y ……….(i)
x2 – y2 = 448 ………(ii)
On substituting x = 14 + y in (ii) we get
(14 + y)2 – y2 = 448
⇒ 196 + y2 + 28y – y2 = 448
⇒ 196 + 28y = 448
⇒ 28y = (448 – 196) = 252
⇒ y = 252/28 = 9
On substituting y = 9 in (i), we get:
x = 14 + 9 = 23
Hence, the required numbers are 23 and 9
Let us consider,
First number = x and
Second number = y
(Assume y is smaller)
As per the statement,
x – y = 14 …..(1)
and x2 – y2 = 448
(x + y) (x – y) = 448
(x + y) x 14 = 448
x + y = 32 ……(2)
Adding (1) and (2),
2x = 46 or x = 23
Subtracting (1) from (2)
2y = 18 or y = 9
Answer:
Numbers are 23 and 9
Let the larger number be x and the smaller number be y.
Then, we have:
x – y = 14 or x = 14 + y ……….(i)
x2 – y2 = 448 ………(ii)
On substituting x = 14 + y in (ii) we get
(14 + y)2 – y2 = 448
⇒ 196 + y2 + 28y – y2 = 448
⇒ 196 + 28y = 448
⇒ 28y = (448 – 196) = 252
⇒ y = 252/28 = 9
On substituting y = 9 in (i), we get:
x = 14 + 9 = 23
Hence, the required numbers are 23 and 9.