Q: There are two numbers whose sum is 15 and whose squares have a sum of 113. Determine the values of these numbers.
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A
3, 2
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B
7, 9
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C
7, 8
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D
7, 4
C
Answer:
C
Explanation:
Given:
x + (15 - x) = 15
x^2 + (15 - x)^2 = 113
Find:
x and (15 - x)
Substitute the first equation into the expression for (15 - x) to get:
x^2 + (15 - x)^2 = 113
x^2 + 225 + x^2 - 30x + x^2 = 113
3x^2 - 30x + 112 = 0
Factor the quadratic equation:
(x - 7)(x - 8) = 0
Solve for x:
x = 7 or x = 8
Therefore, the two numbers are x = 7 and (15 - x) = 8.
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