Question

3x⁴ + 8x³ + 20x² +21x + 18​

Answer 1

Solution :

3x^2 - 21x + 18 = 0

=> 3 (x^2 - 7x + 6) = 0

=> x^2 - 7x + 6 = 0

a = 1 , b = -7 , c = 6

therefore,

b^2 - 4ac

= (-7)^2 - 4 * 1 * 6

= 49 - 24

= 25