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Question
Choose the correct answer from the given four options :
The roots of the equation x2 – 3x – 10 = 0 are
Options
2,- 5
– 2, 5
2, 5
– 2, – 5
Solution
x2 – 3x – 10 = 0
x = `(-(-3) ± sqrt((-3)^2 - 4 xx 1 xx (-10)))/(2 xx 1)`
= `(3 ± sqrt(9 + 40))/(2)`
= `(3 ± sqrt(49))/(2)`
= `(3 + 7)/(2)`
∴ x = `(3 + 7)/(2)` = 5
and
x = `(3 - 7)/(2) = (-4)/(2)` = –2
x = 5, – 2 or – 2, 5.
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