Tony's dinner cost $100. He wanted to pay a tip of 15%. How much did he pay in tips? Just Type the numerical answer. No Units

Given f(x) = 2x^2- 5x+1, determine the function value f(2). do not f(x) = in your answer

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?