Im not sure what to do on question 11

Use the quadratic formula to solve the equation. if necessary, round to the nearest hundredth. x^2 - 23 = 10x a. -1.93, 11.93 b. 1.93, -11.93 c. 1.93, 11.93 d. -1.93, -11.93

The holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost

How many and of which kind of roots does the equation f(x)=x3−x2−x+1