Farmer Bown planted corn and wheat his 1210 acres of land. The cost of planting and arvesting corn (which includes seed, planting, fertilizer, machinery, labor, and other costs) is$275 per acre. The cost of planting wheat is $125 per acre. If Farmer Brown's total cost was $254,750, how many acres of corn did he plant?

Question

Farmer Bown planted corn and wheat  his 1210 acres of land. The cost of planting and arvesting corn (which includes seed, planting, fertilizer, machinery, labor, and other costs) is$275 per acre. The cost of planting wheat is $125 per acre. If Farmer Brown's total cost was $254,750, how many acres of corn did he plant?

anonymous · Answer

$254,750 = corn*$275 + wheat*$125
corn + what = 1210

anonymous · Answer

254,750 = corn*275 + wheat*125
1210 = corn + wheat

254,750 = corn*275 + wheat*125
1210*275= corn*275 + wheat*275

now we have a comparison: corn doesn't change,
all difference must be wheat

anonymous · Answer

can also be solved by substitution

254,750 = corn*275 + wheat*125
--      want to get corn alone:
254,750 - wheat*125= corn*275
corn = 254,750/275 - wheat*125/275

now substitute in the other equation:
1210 = corn + wheat
1210 = 254,750/275 - wheat*125/275 + wheat
1210 = 926.36 - wheat*125/275 + wheat

1210 = 926.36 - wheat*125/275 + wheat |(-926.36)
283.64 = -wheat*125/275 + wheat
283.64 = -0.45 wheat + wheat
283.64 = 0.55 wheat |(x100)
28364 = 55 wheat |(:55)
wheat = 515 acres