Find two real numbers that differ by 5 and have a product of 16
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Originally Posted by pashah Find two real numbers that differ by 5 and have a product of 16 You need that, $\displaystyle x-y=5$ $\displaystyle xy=16$ Thus, $\displaystyle x=y+5$ Thus, $\displaystyle y(y+5)=16$ Thus, $\displaystyle y^2+5y-16=0$ Thus, $\displaystyle y=\frac{-5\pm \sqrt{25+64}}{2}$
I find it interesting how often the quadratic formula ends up being used
Originally Posted by Quick I find it interesting how often the quadratic formula ends up being used Trust me, if cubics were easier to solve we'd be seeing a lot more of those! -Dan
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