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प्रश्न
`8x^2-14x-15=0`
उत्तर
`8x^2-14x-15=0`
⇒`16x^2-28x-30=0`
⇒`16x^2-28x=30`
⇒`(4x)^2-2xx4x xx7/2+(7/2)^2=30+(7/2)^2`
⇒`(4x-7/2)^2=30+49/4=169/4=(13/2)^2`
⇒`4x-7/2=+-13/2`
⇒`4x=7/2=13/2 or 4x-7/2=13/2`
⇒`4x=13/2+7/2=20/2=10 or 4x=-13/2+7/2=6/2=-3`
⇒`x=5/2 or x=-3/4`
Hence, `5/2 and -3/4` are the roots of the given equation.
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