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Find the real numbers whose sum is 8 and whose product is 16​

User DMart
by
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1 Answer

3 votes

Answer:

The number is 4.

Explanation:

First, you have to form equations for the numbers. Let x be the first number and y be the second :


x + y = 8


xy = 16

Next, you have to solve the simultaneous equation by substitution method :


x + y = 8 - - - (1)


xy = 16


y = (16)/(x) - - - (2)


(2)⇒(1)


x + (16)/(x) = 8


\frac{ {x}^(2) + 16 }{x} = 8


{x}^(2) + 16 = 8x


{x}^(2) - 8x + 16 = 0


{(x - 4)}^(2) = 0


x = 4


substitute \: x = 4 \: into \: (1)


4 + y = 8


y = 4

User LarrikJ
by
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