Justin is 3 years older then sam, and justin's age in 2 years will be twice what sam's age was 3 years ago. find their present ages.

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?

Which term best describes the association between variables a and b

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.