Divide 12 into 2 parts such that their sum is74
Answers
Answered by
54
Let x = one of the numbers
Then the other number = 12 - x
Sum of the squares is 74:
x^2 + (12-x)^2 = 74
Solve for x:
x^2 + 144 - 24x + x^2 = 74
2x^2 - 24x + 70 = 0
x^2 - 12x + 35 = 0
Factor:
(x-7)(x-5) = 0
So the numbers are 5 and 7
Answered by
47
- Divide 12 into two parts such that the sum of their square is 74.
To find :-
- The required parts
Solution :-
Let the required part be x and (12 - x)
According to the question,
x² + (12 - x)² = 74
⤇ x² + (12)² - 2 × 12 × x + (x)² = 74
⤇ x² + 144 - 24x + x² = 74
⤇ x² + x² - 24x + 144 = 74
⤇ 2x² - 24x = 74 - 144
⤇ 2x² - 24x = -70
⤇ 2x² - 24x + 70 = 0
⤇ 2(x² - 12x + 35) = 0
⤇ x² - 12x + 35 = 0
⤇ x² - 7x - 5x + 35 = 0
⤇ x(x - 7) - 5(x - 7) = 0
⤇ (x - 7) (x - 5) = 0
Now,
x - 7 = 0
⤇ x = 0 + 7
⤇ x = 7
Then,
x - 5 = 0
⤇ x = 0 + 5
⤇ x = 5
Hence,the required parts will be 5 and 7.
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