Question

a coffee company wants a new flavor of Cajun coffee. how many pounds of coffee worth $9 a pound should be added to 30 pounds of coffee worth $3 a pound to get a mixture worth $7 a pound?

Answer 1

not impossible though
we need a variable for the number of pounds of $9 coffee needed
you pick it

Answer 2

um ... x

Answer 3

ok fine

Answer 4

and you already have 30 pounds of coffee worth $3 a pound for a total cost of \($3\times 30=$90\)

Answer 5

the \(x\) pounds of coffee at $9 will cost \(9x\) dollars for a total cost of
\[9x+90\]dollars

Answer 6

when you add your \(x\) pounds of coffee to the 30 pounds of coffee you will have \(30+x\) pounds of coffee that you want to be worth $7 a pound
set
\[9x+90=7(30+x)\] and solve for \(x\)

Answer 7

correct

Answer 8

x=60