Question 1103055
A-amount of $600/acre land
B-amount of $800/acre land
C-amount of $1000/acre land
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1.{{{A+B+C=900}}}
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{{{600A+800B+1000C=680000}}}
2.{{{3A+4B+5C=3400}}}
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3.{{{A=2C}}}
Substituting eq. 3 into eqs. 1 and 2,
{{{2C+B+C=900}}}
4.{{{B+3C=900}}}
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{{{3(2C)+4B+5C=3400}}}
{{{6C+4B+5C=3400}}}
5.{{{4B+11C=3400}}}
Multiply eq. 4 by 4 and subtract from eq. 5,
{{{4B+11C-4B-12C=3400-3600}}}
{{{-C=-200}}}
{{{C=200}}}
Now work backwards, use the equations and solve for B and A.