Check sibling questions

Example 7 - Solve 2x2 - 5x + 3 = 0 by completing the square - Solving by completing square

Example 7 - Chapter 4 Class 10 Quadratic Equations - Part 2
Example 7 - Chapter 4 Class 10 Quadratic Equations - Part 3 Example 7 - Chapter 4 Class 10 Quadratic Equations - Part 4


Transcript

Example 7 Solve the equation given in Example 3 (2x2 5x + 3 = 0) by the method of completing the square. 2x2 5x + 3 = 0 Dividing by 2 (2 2 5 + 3)/2=0/2 2 2/2 5 /2+3/2=0 x2 5 /2+3/2=0 We know that (a b)2 = a2 2ab + b2 Here, a = x & 2ab = ( 5 )/2 2xb = ( 5 )/2 2b = ( 5)/2 b = ( 5)/(2( 2)) b = 5/4 Now, in our equation x2 5 /2+3/2=0 Adding and subtracting (5/4)^2 x2 5 /2+3/2+(5/4)^2 (5/4)^2=0 x2 +(5/4)^2 5 /2+3/2 (5/4)^2=0 ( 5/4)^2 +3/2 (5/4)^2=0 ( 5/4)^2 +3/2 25/16=0 ( 5/4)^2=25/16 3/2 ( 5/4)^2=(25 3(8))/16 ( 5/4)^2=(25 24)/16 ( 5/4)^2=1/16 ( 5/4)^2=(1/4)^2 Cancelling square 5/4 = 1/4 5/4 = 1/4 Solving So, the roots of the equation are x = 3/2 & x = 1

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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.