3. simplify. a) 5x + 2(x - y) b) 3a - 2b + 4a - 9b c) 2(x - y) + 3(x - y)

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

Eliza wants to make $10,000 from her investments. she finds an investment account that earns 4.5% interest. she decides to deposit $2,500 into an account. how much money will be in her account after 14 years?

Solve the formula ax+ by = c for x.