Can you me on question 3. also tell me how to solve it cause i have a test tomorrow. you!

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

What is the volume of the cone to the nearest cubic millimeter? (use π  = 3.14) a) 46 mm3 b) 128 mm3 c) 183 mm3 d) 275 mm3 diameter = 5 mm height = 7 mm how do you do this problem step by step?

Lines a and b are perpendicular. if the slope of line a is 3, what is the slope of line b?