Can someone help me with this please

Olga bought a new skirt that cost $20. sales tax is 5%. how much did olga pay, including sales tax? 7.

If each bricks costs and he can only buy one brick how much will it cost him to get the material to put around the outside of his garden?

20 points plus brainliest andwer plus my hover hoard im v desperate ! evaluate the polynomial for x=-2 in the equation -3x^3+7x^2-7x-1 (simplify your answer)