2. The sum of two numbers is 18. If the sum of the
reciprocals is
find the numbers.
4.
1
Answers
Correct Question:-
The sum of two numbers is 18. If the sum of their reciprocals is 1/4 , find the numbers.
Answer:-
Given:
Sum of two numbers = 18
Let the numbers be "a" and "b".
Hence,
→ a + b = 18 -- equation (1)
And,
Sum of their reciprocals = 1/4
→ 1/a + 1/b = 1/4
Taking LCM in LHS we get,
→ (b + a) / ab = 1/4
Putting the value of "(a + b)" from equation (1) we get,
→ (18)/ab = 1/4
On cross multiplication we get,
→ 18 * 4 = (1) * (ab)
→ 72 = ab - equation (2)
We know that,
(a - b)² = (a + b)² - 4ab
Hence,
(a - b)² = (18)² - 4 * 72
→ (a - b)² = 324 - 288
→ (a - b)² = 36
→ (a - b)² = (6)²
→ (a - b) = 6 -- equation (3)
Adding equations (1) & (3) we get,
→ a + b + a - b = 18 + 6
→ 2a = 24
→ a = 24/2
→ a = 12
Substitute the value of a in equation (1)
→ a + b = 18
→ 12 + b = 18
→ b = 18 - 12
→ b = 6
Hence, the two numbers are 12 & 6.
Answer:
Step-by-step explanation:
Given
sum of two numbers is 18
sum of their reciprocals is 1/4
Let us consider a and b are two numbers
so a+b = 18
1/a + 1/b = 1/4
Please find the attached file
I hope this will help you..
Good day!