What expression is equivalent to 3^-4.3^6

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ab=9, and ac=12, find hc.

According to statistics a person will devote 32 years to sleeping and watching tv. the number of years sleeping will exceed the number of years watching tv by 18. over a lifetime, how many years will the person spend on each of these activities

Find the equation of the line with slope =8 and passing through (6,53) write your equation in the form y=mx+b