then find the total cost 1250 barrels 27.5 per so mutiply by 1250 and get 34375 total cost
22.5x+35y=34375
we have 2 senctances x+y=1250 22.5x+35y=34375
elimination mulitply first equation by -35 to clear y -35x-35y=-43750 add to second equation -35x-35y=-43750 <u>22.5x+35y=34375 +</u> -12.5x+0y=-9375 -12.5x=-9375 multiply -1 12.5x=9375 divie both sides by 12.5 x=750
subsitute x+y=1250 750+y=1250 subtract 750 y=500
750 barrells of the 22.5 oil should be included and 500 barrells of the 35 oil should be included