Dashaun is running at the speed of 7.2 miles per hour. he starts at mile marker 12. write and solve an equation to find the number of hours dashaun will run until he reaches mile marker 30.
quick! i'll do !

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

700 miles the train takes 5 hours to a travel the distance at what unit rate is the train traveling?