Solve the system by substitution 3x-y=10 2x=y

Imade a fort for my pet gorilla by connecting two boxes. the first box is 555 meters long, 999 meters wide, and 999 meters high. the second box is 333 meters long, 888 meters wide, and 222 meters high.how many cubic meters of space does my gorilla have to play in her fort?

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Solve the equation - 2(m -30) = -6m a-15 b-13 c-8 d8