-3x - 7y=2
x + 3y = -2
solving systems by elimination

In angle pqr find the measure of

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?

Ashipment of 18 cars, some weighing 3000lb a piece and th eothers 5000lb each, has a total weight of 30 tons. find the number of each kind of car.