Please help me please I will 5 star worth 30 pts​

In a school 2/3 of the students study a language of those who study a language 2/5 study french

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?

If x = -2, then x 2-7x+10 equals a. 0 b.20 c.28