I dont understand can someone give a brief explaintionpleasee amd thanku

3x + 4y = 5 x- 3y = -7 solve by substitution

Alcoa was $10.02 a share yesterday. today it is at $9.75 a share. if you own 50 shares, did ou have capital gain or loss ? how much of a gain or loss did you have ? express the capital gain/loss as a percent of the original price

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.