212k views
3 votes
Using the discriminant, determine the number of real solutions.

2x^2+7x-15=0

A. no real solutions
B. one real solution
C. two real solutions.

User Sfuqua
by
5.2k points

1 Answer

4 votes

Answer:

C. two real solutions

Explanation:

Your quadratic matches the form ...

ax^2 +bx +c = 0

for the values a=2, b=7, c=-15.

The discriminant is ...

d = b^2 -4ac

For your values of a, b, c, the discriminant value is ...

d = 7^2 -4(2)(-15) = 169

The discriminant is positive, indicating there are two real solutions.

_____

When the discriminant is negative, there are no real solutions, only complex solutions.

When the discriminant is zero, there is one real solution.

__

This equation factors as (2x-3)(x+5) = 0 and has solutions x=3/2, x=-5.

User Vilalabinot
by
5.3k points