Question

the sum of roots of the quadratic equation3x2-9x+5=0 is​

Answer 1

3x²-9x+5 = 0.

multiplying the equation by 3.

9x²-27x+15 =0.

(3x)² - 2 * 3x * 9/2 + (9/2)² - (9/2)² + 15 = 0.

(3x - 9/2)² - 81/4 + 15 = 0.

(3x - 9/2)² -21/4 = 0.

(3x - 9/2 )² = 21/4.

3x - 9/2 = +/- √21/4.

3x = +/- √21/4 + 9/2.

X = (+/-√21/4 + 9/2) ÷ 3.

.

so, the 1st root is,

X= (√21/4 + 9/2) ÷ 3.

and 2nd root is,

X = (-√21/4 + 9/2) ÷ 3.