Solve each system by elimination

11 – 2c = 3d
2c - 7d = -9

Daniel bought a computer game for $25 and later sold it to thomas for a 40% profit. how much did daniel sell the computer game for?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Shelly bought a house five years ago for $150,000 and obtained an 80% loan. now the home is worth $140,000 and her loan balance has been reduced by $12,000. what is shelly's current equity?