Question 34899
1)  2X+3Y=89  &  X+Y=40 THEN X=40-Y & 2(40-Y)+3Y=89 OR 80-2Y+3Y=89 OR

Y=9 THEN X=40-9 OR 31 

PROOF 2*31+3*9=89 OR 62+27=89 AND 31+9=40

2) (6.5,8)(4,9) PROVIDES A SLOPE OF (9-8)/(4-6.5) OR 1/-1.5  WHICH SAYS THAT FOR EVERY DOLLAR INCREASE IN A POUND OF COFFEE YOU LOSE 1.5 MILLION POUNDS. THUS A DROP IN PRICE FROM 8 TO 6 POUNDS SHOULD INCREASE 2*1.5 MILLION SALES OR 6.5+3=9.5 MILLION POUNDS @ $6 PER POUND.