What is the total mass (in tonnes) of 3 500 books each of mass 800 grams?

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?

Ihave a triangle with a 60 degree angle. lets use d for that angle. what are the values of e and f if d is 60 degrees? and what do you notice about the values of e and f?

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b