If the sum of 28% is 100.8, what is the sum

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?

2y= 3 2 x−2 y = − 1 3 x + 1 y=− 3 1 x+1

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)