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Question
Solve the following quadratic equation using formula method only
`3"x"^2 + 2 sqrt 5x - 5 = 0 `
Solution
`3"x"^2 + 2 sqrt 5x - 5 = 0 `
a = 3 ; b = `2 sqrt 5` ; c = -5
D = b2 - 4ac
`=(2 sqrt 5)^2 - 4(3)(-5)`
= 20 +60
= 80
X = `(- "b" ± sqrt ("b"^2 - 4 "ac"))/(2a)`
X = `(-(2 sqrt 5) +- sqrt 80)/6 `
X = `(-(2 sqrt 5) +- 4 sqrt 5)/6 `
X = `(-(2 sqrt 5) + 4 sqrt 5)/6 ` , X = `(-(2 sqrt 5) - 4 sqrt 5)/6 `
X = `sqrt 5/3` , X = `- sqrt 5`
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Solution :
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