document.write( "Question 400613: Ms. Butler is filling planter boxes with soil. She has soil that is 28% sand, and she buys 6 pounds of a commercial potting soil that is 33% sand. She mixes some of her soil with the 6 pounds of commercial potting soil. The resulting soil mixture is 31% sand. How many pounds of her soil did Ms. Butler use? \n" ); document.write( "

Algebra.Com's Answer #283584 by josmiceli(19441) $\"\"$ $\"About$

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In words:
\n" ); document.write( "(sand in final mixture)/(sand + soil in final mixture) = 31%
\n" ); document.write( "Let $\"x\"$ = pounds of her soil she used
\n" ); document.write( "given:
\n" ); document.write( " $\".28x\"$ = pounds of sand in her soil
\n" ); document.write( " $\".33%2A6+=+1.98\"$ pounds of sand in commercial potting soil
\n" ); document.write( "--------------------------
\n" ); document.write( " $\"%28.28x+%2B+1.98%29%2F%286+%2B+x%29+=+.31\"$
\n" ); document.write( " $\".28x+%2B+1.98+=+.31%2A%286+%2B+x%29\"$
\n" ); document.write( " $\".28x+%2B+1.98+=+1.86+%2B+.31x\"$
\n" ); document.write( " $\".03x+=+.12\"$
\n" ); document.write( " $\"x+=+4\"$
\n" ); document.write( "She needs 4 pounds of her soil
\n" ); document.write( "check:
\n" ); document.write( " $\"%28.28%2A4+%2B+1.98%29%2F%286+%2B+4%29+=+.31\"$
\n" ); document.write( " $\"%281.12+%2B+1.98%29%2F10+=+.31\"$
\n" ); document.write( " $\"3.1%2F10+=+.31\"$
\n" ); document.write( " $\"3.1+=+3.1\"$
\n" ); document.write( "OK \n" ); document.write( "

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