I need help first one say "a" and the other one say "b"

1. are the triangles similar and if so why? what is the value of x? show your work.

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?

What is the solution to the system of equations? (–2, –8) (–1, –5) (0, –2) (2, 4)