Find the distance between j and k

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Solve for x: 5/3 x = 20/21 it's fraction. remember to simplify your fraction

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.