Answer: d. 21
Step-by-step explanation:
The formula to find a discriminant is b^2-4ac.
ax^2+bx+c is the quadratic equation. In your equation, -1 is a, -1 is b, and 5 is c. Now we can plug in the numbers into the discriminant formula b^2-4ac!
(-1)^2-4(-1)(5)=
1-4(-5)
1+20
21
The discriminant is 21.
Hope this helps!
