the sum of two number is 6 and the sum of their squares is 28. Find the exact values of these numbers
Answers
Step-by-step explanation:
Given:-
- The sum of two numbers
- The sum of their squares
To Find:-
- The two numbers
Correct Question:-
The sum of two number is 6 and the sum of their squares is 26. Find the exact values of these numbers
Solution:-
Let two numbers be x and y
→x+y=6----(i)
→x²+y²=26
Now we have to find xy
So,
(x+y)²=x²+y²+2xy
(6)²=26+2xy
36=26+2xy
2xy=36-26
2xy=10
xy=5
Now we have to find the x-y
(x-y)²=(x+y)²-4xy
(x-y)²=(6)²-4(5)
(x-y)²=36-20
(x-y)²=16
x-y=4---(ii)
Adding (i) and (ii)
x+y=6
x-y=4
--------
2x=10
x=5
x+y=6
y=6-5=1
Required numbers=1 and 5
Correct Question -
The sum of two number is 6 and the sum of their squares is 26. Find the exact values of these numbers.
[ In the original question, the value of the sum of the squares is given wrong, it will be 26 not 28 ]
Solution -
• The sum of two numbers is 6
• The sum of their squares is 26.
We have to find the exact value of these two numbers.
Let us assume that they are a and b such that a,b € I
a,b € I a, b ≥ 1 . Either a or b or both can not be zero as no such solutión exists for that case.
As per the questión
a + b = 6
Squaring this
> a² + b² + 2ab = 36 [ a² + b² < 36 as 2ab ≥ 1 ]
Now , the sum of the squares is 28
So, a² + b² = 36
> 2ab + 26 = 36
> 2ab = 36 - 26 = 10
> ab = 5
There are two cases arising from ab = 5
- a = 1 and b = 5
- a = 5 and b = 1.
Both of these hold true here .
Answer - The exact values of the numbers satisfying the above property are tuples of (1,5) .
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