Which system of linear equations can be solved using equation [[x],[y]]= [[(1)/(4),(3)/(4)],[1,2]][[28],[-12 ]]

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Are the corresponding angles congruent? explain why or why not.