Advertisements
Advertisements
Question
The difference between two positive numbers is 4 and the difference between their cubes is 316.
Find : Their product
Solution
Given difference between two positive numbers is 4 and difference between their cubes is 316.
Let the positive numbers be a and b
a - b = 4
a3 - b3 = 316
Cubing both sides,
(a - b)3 = 64
a3 - b3 - 3ab(a - b) = 64
Given a3 - b3 = 316
So 316 - 64 = 3ab(4)
252 = 12ab
So ab = 21; product of numbers is 21
APPEARS IN
RELATED QUESTIONS
Expand : ( 5a - 3b + c )2
Expand : `( x - 1/x + 5)^2`
If a2 + b2 + c2 = 50 and ab + bc + ca = 47, find a + b + c.
In the expansion of (2x2 - 8) (x - 4)2; find the value of coefficient of x2
If 2( x2 + 1 ) = 5x, find :
(i) `x - 1/x`
(ii) `x^3 - 1/x^3`
If a2 + b2 = 34 and ab = 12; find : 3(a + b)2 + 5(a - b)2
If a2 + b2 = 34 and ab = 12; find : 7(a - b)2 - 2(a + b)2
Find the value of 'a': 9x2 + (7a - 5)x + 25 = (3x + 5)2
If x = `1/[ 5 - x ] "and x ≠ 5 find "x^3 + 1/x^3`
If x = `1/( x - 5 ) "and x ≠ 5. Find" : x^2 - 1/x^2`
