How do you solve the equation 2x^2+5x-3=0 by using the quadratic formula?

1 Answer
Dec 26, 2016

The two solutions are x = 0.5 and x = -3

Explanation:

Since this question is given in standard form, meaning that it follows the form: ax^(2) + bx + c = 0, we can use the quadratic formula to solve for x:

![http://www.1728.org/http://quadratc.htm](https://useruploads.socratic.org/X4QibY3hTiagek8Kw3kN_quadratc.png)
I think it's worthwhile to mention that a is the number that has the x^2 term associated with it. Thus, it would be 2x^(2) for this question.b is the number that has the x variable associated with it and it would be 5x, and c is a number by itself and in this case it is -3.

Now, we just plug our values into the equation like this:

x = (- (5) +- sqrt((5)^(2) - 4(2)(-3)))/(2(2))

x = (-5 +-sqrt(25+24))/4

x = (-5 +- sqrt(49))/4

For these type of problems, you will obtain two solutions because of the +- part. So what you want to do is add -5 and sqrt(49) together and divide that by 4:

x = (-5+sqrt(49))/4
x = 2/4= 0.5

Now, we subtract sqrt(49) from -5 and divide by 4:

x = (-5-sqrt(49))/4
x = -12/4 = -3

Therefore, the two possible solutions are:
x = 0.5 and x = -3