One book costs £1.99 how much do four books cost?

Ineed if you could explain and give me the answer you! this needs done

Carmen begins her next painting on a rectangular canvas that is 82.7 cm long and has a area of 8,137.68 cm2. will the painting fit in a frame with an opening that is 82.7 cm long and 95 cm wide? explain

Ten times the square of a non-zero number is eqaul to ninety times the number