Find the roots of the quadratic equation 3x 2 - 7x - 6 = 0

This question is similar to Example 13 (i) Chapter 4 Class 10 - Quadratic Equations

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  1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards

Transcript

Question 1 โ€“ Choice 1 Find the roots of the quadratic equation 3๐‘ฅ2 โˆ’ 7๐‘ฅ โˆ’ 6 = 0. Given 3x2 โ€“ 7x โˆ’ 6 = 0 Comparing equation with ax2 + bx + c = 0 Here, a = 3, b = โ€“7, c = โˆ’6 We know that, D = b2 โ€“ 4ac D = (โ€“7)2 โ€“ 4 ร— 3 ร— (โˆ’6) D = 49 + 72 D = 121 So, the roots of the equation is given by x = (โˆ’ ๐’ƒ ยฑ โˆš๐‘ซ)/๐Ÿ๐’‚ Putting values x = (โˆ’(โˆ’7) ยฑ โˆš121)/(2 ร— 3) x = (๐Ÿ• ยฑ ๐Ÿ๐Ÿ)/๐Ÿ” Solving x = (7 + 11)/6 x = 18/6 x = 3 x = (7 โˆ’ 11)/6 x = (โˆ’4)/6 x = (โˆ’๐Ÿ)/๐Ÿ‘ Hence, the roots of the equation are 3 and (โˆ’2)/3 .

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.