The answer of this problem because I am currently having trouble with this topic and teach me how to solve it thanks!

In the diagram, the measure of angle 9 is 85° which angle must also measure 85°?

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?

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.