Bonjour help me please je ny arrive pas ..merci​

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

()1. how do you find range? 2.the following set of data is to be organized into a histogram. if there are to be five intervals on the graph, what should the length of each interval be? 30, 34, 23, 21, 27, 25, 29, 29, 25, 23, 32, 31

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.