Question

Give the values of a, b, and c from the standard form of the equation (2x + 1)(x - 2) = 0.

A. a = 3, b = 1, c = -1
B. a = 2, b = 5, c= -2
C. a = 2, b = -3,c = -2

Answer 1

Given:

The equation is:

`(2x+1)(x-2)=0`

To find:

The values of a, b and b from the standard form.

Solution:

The standard form of a quadratic equation is:

`ax^2+bx+c=0` ....(i)

We have,

`(2x+1)(x-2)=0`

In can be rewritten as

`2x(x)+(2x)(-2)+(1)(x)+(1)(-2)=0`

`2x^2-4x+x-2=0`

`2x^2-3x-2=0` ...(ii)

On comparing (i) and (ii), we get

`a=2,b=-3,c=-2`

Therefore, the correct option is C.