document.write( "Question 578502: A, B, & C have equal incomes from investments. A has invested $2000 less than B and $2500 more than C . The rate of interest received by A is 1 per cent more than that received by B and 2 per cent less than that received by C. How much has A invested? Pls. help me solve this. I've been working on it for 2 hours now and still can't come up with the equation and the answer. Thanks. \n" ); document.write( "
Algebra.Com's Answer #370691 by ankor@dixie-net.com(22740)\"\" \"About 
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A, B, & C have equal incomes from investments.
\n" ); document.write( "A has invested $2000 less than B and $2500 more than C .
\n" ); document.write( " The rate of interest received by A is 1 per cent more than that received by B
\n" ); document.write( " and 2 per cent less than that received by C.
\n" ); document.write( " How much has A invested?
\n" ); document.write( ":
\n" ); document.write( "You're right, this is a doozy
\n" ); document.write( ":
\n" ); document.write( "Let A, B, C = amt of each investment
\n" ); document.write( "Let a, b, c = interest rate of each in decimal form
\n" ); document.write( ":
\n" ); document.write( "Given that incomes are equal:
\n" ); document.write( "aA = bB = cC
\n" ); document.write( "Write an equation for each statement:
\n" ); document.write( ":
\n" ); document.write( "Get B and C in terms of A, and get b & c in terms of a
\n" ); document.write( ":
\n" ); document.write( "\" A has invested $2000 less than B.\"
\n" ); document.write( "A = B-2000
\n" ); document.write( "or
\n" ); document.write( "B = (A+2000)
\n" ); document.write( "and
\n" ); document.write( "\"$2500 more than C\"
\n" ); document.write( "A = C+2500
\n" ); document.write( "or
\n" ); document.write( "C = (A-2500)
\n" ); document.write( ":
\n" ); document.write( "\" The rate of interest received by A is 1 per cent more than that received by B\"
\n" ); document.write( "a = b+.01
\n" ); document.write( "or
\n" ); document.write( "b =(a-.01)
\n" ); document.write( ":
\n" ); document.write( "\"and 2 per cent less than that received by C.\"
\n" ); document.write( "a = c-.02
\n" ); document.write( "or
\n" ); document.write( "c = (a+.02)
\n" ); document.write( ":
\n" ); document.write( "We know
\n" ); document.write( "aA = bB
\n" ); document.write( "replace b with (a-.01) and B with (A+2000)
\n" ); document.write( "aA = (a-.01)(A+2000)
\n" ); document.write( "FOIL the right
\n" ); document.write( "aA = aA + 2000a - .01A - 20
\n" ); document.write( "Subtract aA from both sides, add 20 to each side
\n" ); document.write( "2000a - .01A = 20
\n" ); document.write( ":
\n" ); document.write( "aA = cC
\n" ); document.write( "replace c with (a+.02) and C with (A-2500)
\n" ); document.write( "aA = (a+.02)(A-2500)
\n" ); document.write( "FOIL the right
\n" ); document.write( "aA = aA - 2500a + .02A - 50
\n" ); document.write( "Subtract aA from both sides, add 50 to each side
\n" ); document.write( "-2500a + .02A = 50
\n" ); document.write( ":
\n" ); document.write( "Use elimination with these two equation, multiply the 1st on by 2, add to the 2nd
\n" ); document.write( "4000a - .02A = 40
\n" ); document.write( "-2500a +.20A = 50
\n" ); document.write( "-------------------adding eliminates A, find a
\n" ); document.write( "1500a = 90
\n" ); document.write( "a = \"90%2F1500\"
\n" ); document.write( "a = .06, so 6% is the int rate of the A investment
\n" ); document.write( "then
\n" ); document.write( "b = .06 - .01
\n" ); document.write( "b = .05, 5% is the int rate of the B investment
\n" ); document.write( "and
\n" ); document.write( "c = .06 +.02
\n" ); document.write( "c = .08, 8% is the int rate of the C investment
\n" ); document.write( ":
\n" ); document.write( "Remember aA = bB
\n" ); document.write( ".06A = .05B
\n" ); document.write( "Replace B with (B+2000)
\n" ); document.write( ".06A = .05(A+2000)
\n" ); document.write( ".06A = .05A + 100
\n" ); document.write( ".06A - .05A = 100
\n" ); document.write( ".01A = 100
\n" ); document.write( "A = \"100%2F.01\"
\n" ); document.write( "A = $10,000 investment which is what they want
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "You can check this by finding the actual interest from B & C, confirming that they are all equal. I did this and found each had a return of $600, but don't take my word for it. C\r
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