SOLUTION: I was wondering if someone who is an expert in this area could help me? I don't understand how to obtain the answer for the following problem. In order for me to get a good grade,

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: I was wondering if someone who is an expert in this area could help me? I don't understand how to obtain the answer for the following problem. In order for me to get a good grade,       Log On


   

Question 360730: I was wondering if someone who is an expert in this area could help me? I don't understand how to obtain the answer for the following problem. In order for me to get a good grade, I need to show all the steps I used to get the answer. I would be most appreciated and happy if you could show me how to solve the following problem:
Directions: Use the discriminant to determine the number and type of solutions for the given equation.
X^2+ 3x-4=0
according to my book it states that the answer is:
two rational solutions.
My question is how do I know this? What steps do I have to take to determine this? I thank you for your help!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
From x%5E2%2B3x-4 we can see that a=1, b=3, and c=-4


D=b%5E2-4ac Start with the discriminant formula.


D=%283%29%5E2-4%281%29%28-4%29 Plug in a=1, b=3, and c=-4


D=9-4%281%29%28-4%29 Square 3 to get 9


D=9--16 Multiply 4%281%29%28-4%29 to get %284%29%28-4%29=-16


D=9%2B16 Rewrite D=9--16 as D=9%2B16


D=25 Add 9 to 16 to get 25


So the discriminant is D=25


Since the discriminant is greater than zero, this means that there are two real solutions.


Note: because the discriminant is a perfect square, this means that the two real solutions are also two rational solutions.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim