SOLUTION: Determine the type (real or complex) and number of the solutions of each of the following equations. Justify your answer. x^2 + 3x - 15 = 0 Thank you

Algebra ->  Equations -> SOLUTION: Determine the type (real or complex) and number of the solutions of each of the following equations. Justify your answer. x^2 + 3x - 15 = 0 Thank you      Log On


   

Question 193949This question is from textbook
: Determine the type (real or complex) and number of the solutions of each of the following equations. Justify your answer.
x^2 + 3x - 15 = 0 Thank you This question is from textbook

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

From x%5E2%2B3x-15 we can see that a=1, b=3, and c=-15


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


D=%283%29%5E2-4%281%29%28-15%29 Plug in a=1, b=3, and c=-15


D=9-4%281%29%28-15%29 Square 3 to get 9


D=9--60 Multiply 4%281%29%28-15%29 to get %284%29%28-15%29=-60


D=9%2B60 Rewrite D=9--60 as D=9%2B60


D=69 Add 9 to 60 to get 69


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