Question

Select the two values of x that are roots of this equation.

2x - 5 = -3x2
O A. X = 1
B. x= -1
C. X = 3
D. x =

Answer 1

x = -
`(5)/(3)` , x = 1

Explanation:

Given

2x - 5 = - 3x² ( add 3x² to both sides )

3x² + 2x - 5 = 0 ← in standard form

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

product = 3 × - 5 = - 15 and sum = + 2

The factors are - 3 and + 5

Use these factors to split the x- term

3x² - 3x + 5x - 5 = 0 ( factor the first/second and third/fourth terms )

3x(x - 1) + 5(x - 1) = 0 ← factor out (x - 1) from each term

(x - 1)(3x + 5) = 0 ← in factored form

Equate each factor to zero and solve for x

3x + 5 = 0 ⇒ 3x = - 5 ⇒ x = -
`(5)/(3)`

x - 1 = 0 ⇒ x = 1