Three times the difference of a number and 9 is -3. find the number

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 expression in factored form? -x^2 + 3x + 28 a. (x-7)(x-4) b. -(x-7)(x+4) c. (x+4)(x+7) d. -(x-4)(x+7)

Which is greater, 7 p 5 or 7 c 5? 7p5 7c5