Check sibling questions

Example 8 - Find roots of 5x2 - 6x - 2 = 0 by completing sq - Solving by completing square

Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 2
Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 3
Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 4

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Transcript

Example 8 Find the roots of the equation 5x2 6x 2 = 0 by the method of completing the square. 5x2 6x 2 = 0 Dividing by 5 (5 2 6 2)/5=0/5 5 2/5 6 /5 2/5=0 x2 6 /5 2/5=0 We know that (a b)2 = a2 2ab + b2 Here, a = x & 2ab = ( 6 )/5 2xb = ( 6 )/5 2b = ( 6)/5 b = ( 6)/(5 ( 2)) b = 3/5 Now, in our equation x2 6 /5 2/5=0 Adding and subtracting (3/5)^2 x2 6 /5 2/5+(3/5)^2 (3/5)^2=0 x2 6 /5+(3/5)^2 2/5 (3/5)^2=0 ( 3/5)^2 2/5 (3/5)^2=0 ( 3/5)^2=(3/5)^2+2/5 ( 3/5)^2=9/25+2/5 ( 3/5)^2=(9 + 2(5))/25 ( 3/5)^2=(9 +10)/25 ( 3/5)^2=19/25 ( 3/5)^2=( 19)^2/5^2 Cancelling squares both sides 3/5 = 19/5 3/5 = 19/5 Solving So, x = ( (19 )+ 3)/5 and x = ( 19 + 3)/5 are the roots of the equation .

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.