Maria is planning a party. nancy, her friend, suggest that she should order three pizzas for every seven people. if she is expecting 21 people at the party, how many pizzas should she order?

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

For what values of x is x2 + 2x = 24 true?

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.