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Question
Solve the following equation using the formula:
x2 – 10x + 21 = 0
Solution
x2 – 10x + 21 = 0
Here a = 1, b = –10 and c = 21
Then `x = (-b +- sqrt(b^2 - 4ac))/(2a)`
= `(-(-10) +- sqrt((-10)^2 - 4(1)(21)))/(2(1))`
= `(10 +- 4)/2`
= `(10 + 4)/2` and `(10 - 4)/2`
= 7 and 3
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