Question

Solve by using the method of completing the square :

3x^2 - x - 2 = 0

Answer 1

hey mate
here's the solution

Answer 2

Given method:

To complete the square:

3x² - x - 2 = 0

==> 3x² - x = 2

Dividing both sides by 3

==> x² - x / 3 = 2/ 3

==> x² - 2*x *1/ 6 = 2 /3

Adding 1/36 to both sides

==> x² - 2*x*1/6 + 1/36 = 1/36 + 2/3

(a-b)²=a²+2ab+b² Hence:

==> ( x - 1/6 )² = (1 + 24 ) / 36

==> (x-1/6) ²= 25/36

==> x-1/6 = 5/6 or -5/6

Case 1

x- 1/6 = 5/6

==> x =5/6+1/6

==> x = 6/6

==>x=1

Case 2

==> x-1/6=-5/6

==> x=-5/6+1/6

==>x=-4/6

==>x=-2/3

The value of x is 1 and -2/3

Hope it helps you dear

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