Question

8x²-70x+85 what will be it's factories

Answer 1

Given:-

•p(x)=0

→8x²-70x+85=0

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To Find:-

Find its Factors?

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AnsWer:-

→8x²-70x+85=0

→S=-70

→P=680

[If we try Spiliting the Middle term, it would be a Long process, Hence we will use DISCRIMINANT FORMULA]

๛Discriminant Formula↓

→d=b²-4ac

•a=8,b=-70,c=85

→d=(-70)²-4×8×85

→d=4900-2720

→d=2180

→√d=±2√545

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๛Taking x(+)=$\frac{-b+ \sqrt{d}}{2a}$

→x(+)=$\frac{-(-70)+ 2 \sqrt{545}}{2×8}$

→x(+)=$\frac{70+2 \sqrt{545}}{16}$

→$\frac{\cancel{2}(35+ \sqrt{545})}{\cancel{16}}$

→$\frac{35+ \sqrt{545}}{8}$

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๛Taking x(-)=$\frac{-b- \sqrt{d}}{2a}$

→x(+)=$\frac{-(-70)- 2 \sqrt{545}}{2×8}$

→x(+)=$\frac{70-2 \sqrt{545}}{16}$

→$\frac{\cancel{2}(35- \sqrt{545})}{\cancel{16}}$

→$\frac{35- \sqrt{545}}{8}$

$\rule{200}{1}$

★x=$\frac{35± \sqrt{545}}{8}$ ★

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