Question

find the root of given equation by completing the square method 3 x square - 5 x + 2 = 20​

Answer 1

$3x ^{2} - 5x + 2 = 20$
make the coefficient of x^2 unity.

Now divide by 3 on both LHS and RHS.

x^2-5x+2=20

x^2-5x=18

Add the half of coefficient of X.

x^2-5x+(5/2)^2=18+(5/2)^2

(x-5/2)^2=18+25/4

(x-5/2)^2=72+25/4

(x-5/2)^2=97/4

(x-5/2)=+√97/4 or-√97/4