Sevent times the sum of a number, n,and four

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14

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?

Percy rides his bike 11.2 miles in 1.4 hours at a constant rate. write an equation to represent the proportional relationship between the number of hours percy rides, x, and the distance in miles, y, that he travels.