document.write( "Question 206686: Please help, I am stuck...18/40=45/? I can't remember how to do these! Can anyone help me? \n" ); document.write( "
Algebra.Com's Answer #156220 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Note: it is more common to see an 'x' instead of a '?' for unknown numbers.\r
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\n" ); document.write( "\n" ); document.write( "\"18%2F40=45%2Fx\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"%2818%2F40%29%2Ax=45\" Multiply both sides by x\r
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\n" ); document.write( "\n" ); document.write( "\"18%2Ax=45%2A40\" Multiply both sides by 40\r
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\n" ); document.write( "\n" ); document.write( "\"18%2Ax=1800\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"x=1800%2F18\" Divide both sides by 18\r
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\n" ); document.write( "\n" ); document.write( "\"x=100\" Simplify\r
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\n" ); document.write( "\n" ); document.write( "So the solution is \"x=100\"
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