.6666667 hope I helped you!
First set everything to 0.

Giving you A= 1 , B= 1 and C= -5
Then input everything into the quadratic formula and either solve by hand or use a calculator.
Note exact values are found by hand, decimals are found using a calculator.
Answer: -12
Work: Since -4 is in parentheses, I did -4 / 5 first. After doing the division, I had gotten -0.8. I multiplied -0.8 by 15, and had gotten -12.
Step-by-step explanation:
The probability would be 12/16 or 75%.
Hope this helps!