document.write( "Question 183884: A landscaper wants to combine golden landscape rock with rust-colored landscape rock to make a mix. The golden rock costs $0.59 per pound and the rust-colored rock cost $0.49 per pound. If the landscaper buys 90 pounds of the mixture costing a total of $48.60, how much of the golden rock did he buy? \n" ); document.write( "
Algebra.Com's Answer #137962 by tvandenberg(45)\"\" \"About 
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G = amount of golden rock
\n" ); document.write( "R = amount of rusted rock
\n" ); document.write( "---
\n" ); document.write( "(a) G + R = 90
\n" ); document.write( "(b) 0.59*G + 0.49*R = 48.60
\n" ); document.write( "---
\n" ); document.write( "We need to now solve (a) for either G or R, I randomly chose G...
\n" ); document.write( "(a') G = 90 -R
\n" ); document.write( "---
\n" ); document.write( "Substitute (a') into (b)
\n" ); document.write( "(b') 0.59*(90-R) + 0.49*R = 48.60
\n" ); document.write( "---
\n" ); document.write( "Some \"simple\" algebra...
\n" ); document.write( "53.10 - 0.59*R + 0.49*R = 48.60
\n" ); document.write( "4.50 = 0.1*R
\n" ); document.write( "R = 45
\n" ); document.write( "---
\n" ); document.write( "Back to (a')...
\n" ); document.write( "G = 90 - 45 = 45
\n" ); document.write( "---
\n" ); document.write( "Check your answers:
\n" ); document.write( "(a) 45 + 45 = 90 (good)
\n" ); document.write( "(b) 0.59*(45) + 0.49*(45) = 48.60 (good) \n" ); document.write( "
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