How to solve for three unkowns using conservation of momentum and kinetic energy equations

Factorize: x^2+8x+10 i just solved it but i don't know if the process is correct

Rosy waxes 2/3 of her car with 1/4 bottle of car wax.at this rate,what fraction of the bottle of car wax will rosey use to wax her entire car

The curved part of the figure is the semicircle what is the best approximation for the area of this figure