Question 160552
Let x=amount of regular coffee needed

Now we know that the cost of the regular coffee (4x) plus the cost of the gourmet coffee(7*40) has to equal the cost of the final mixture (5(40+x)).  So:
4x+7*40=5(40+x) get rid of parens (distributive)
4x+280=200+5x subtract 200 and also 4x from each side
4x-4x+280-200=200-200+5x-4x  collect like terms
80=x or
x=80 lbs -----------------amount of regular coffee needed
CK
4*80+7*40=5*120
320+280=600
600=600

Hope this helps-----ptaylor