Question

X+y = 8 , xy =15/4 find x-y

Answer 1

hope this answer helps

Answer 2

$We \:have \: x + y = 8 \: ---(1) \\and \: xy = \frac{15}{4} \: ---(2)$

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By Algebraic Identity ,

$\pink { ( x - y )^{2} = ( x + y )^{2} - 4xy }$

$= 8^{2} - 4 \times \frac{15}{4} \\= 64 - 15 \\= 49$

$Now, \: \red { x - y } = \pm \sqrt{49} \\= \pm \sqrt{7^{2}} \\= \pm 7$

Therefore.,

$\red { Value \: of \: x - y } \green {= \pm 7 }$

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