Please help I'm kinda stuck here!!

Will rate 5star

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?

On a piece of paper graph f(x)=5•(0.4)^x

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =