Question

Zeroes of polynomial p(x)=2x^2-9-3x are :​

Answer 1

x = -
`(3)/(2)`, x = 3

Explanation:

To find the zeros let p(x) = 0 , that is

2x² - 3x - 9 = 0

Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term.

product = 2 × - 9 = - 18 and sum = - 3

The factors are - 6 and + 3

Use these factors to split the x- term

2x² - 6x + 3x - 9 = 0 ( factor the first/second and third/fourth terms)

2x(x - 3) + 3(x - 3) = 0 ← factor out (x - 3) from each term

(x - 3)(2x + 3) = 0

Equate each factor to zero and solve for x

2x + 3 = 0 ⇒ 2x = - 3 ⇒ x = -
`(3)/(2)`

x - 3 = 0 ⇒ x = 3