Question

Solve the following quadratic equation by using the formula method:

x² − 2x − 3 = 0

Answer 1

x² − 2x − 3 = 0

For the equation, the coefficients are:

 a = 1, b = −2 and c = −3

Apply the quadratic equation formula:

`x = (-b +- sqrt(b^2-4ac))/(2a)` 

= `(-(-2) +- sqrt((-2)^2-4(1)(−3)))/(2(1))`  

= `(2 +- sqrt(4 - (-12)))/2`

= `(2 +- sqrt(4 + 12))/2`

= `(2 +- sqrt(16))/2`

= `(2 +- 4)/2`

This gives two solutions:

= `(2 + 4)/2` or `(2 - 4)/2`

= `6/2` or `(-2)/2`

= 3 or −1

The solutions to the quadratic equation x = 3 or x = −1.