A car is travelling at a constant speed until the car’s brakes are applied. The car’s speed changes at a rate given by0.08t ms^-2 after the brakes are applied, where t s is the time since the brakes were applied. 3 seconds after the brakes are applied, the speed of the car is 5 ms^-1. How far will the car travel with the brakes applied before it stops

These are the multiples of 15 but what you are probably asking or what are the factors of 15

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.