What is the solution for the following system of equations? 7x+10y=4

How many sides does a regular polygon have if each exterior angle measures 72a.3b.4c.5d.6

Which speed is the fastest (use 1 mile ≈ 1.6 kilometers)? a. 12 miles/hour b. 18 feet/second c. 19 kilometers/hour d. cannot be determined

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document