Question 189324
4r+7g=5(g+r)
4r+7*40=5(40+r)
4r+280=200+5r
4r-5r=200-280
-r=200-280
-r=-80
r=80 ans. for the pounds of regular coffee.
Proof:
4*80+7*40=5(40+80)
320+280=5*120
600=600