document.write( "Question 208439: 20-4 over 5x is greater then or equal to 16?
\n" ); document.write( "greater then=> (if i have it wrong, its less then)
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Algebra.Com's Answer #157657 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
you manipulate inequalities much the same way you manipulate equalities.
\n" ); document.write( "the only real difference is that if you multiply both sides of an inequality by -1 then you reverse the inequality.
\n" ); document.write( "example:
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\n" ); document.write( "equality:
\n" ); document.write( "a = b
\n" ); document.write( "multiply both sides by -1 to get:
\n" ); document.write( "-a = -b
\n" ); document.write( "the signs are reversed and the equality is preserved.
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\n" ); document.write( "inequality:
\n" ); document.write( "a > b
\n" ); document.write( "multiply both sides by -1 to get:
\n" ); document.write( "-a < -b
\n" ); document.write( "the signs are reversed and the inequality is reversed. where it said > now it says <.
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\n" ); document.write( "your equation looks like this:
\n" ); document.write( "(20-4)/5x >= 16
\n" ); document.write( "as far as i can tell.
\n" ); document.write( "to solve this you do the following:
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\n" ); document.write( "multiply both sides by x to bring the x over to the right side of the equation and remove it from the denominator.
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\n" ); document.write( "you get:
\n" ); document.write( "(20-4)/5 >= 16 * x
\n" ); document.write( "which becomes:
\n" ); document.write( "16/5 >= 16x
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\n" ); document.write( "divide both sides by 16 to get:
\n" ); document.write( "16/(16*5) >= x
\n" ); document.write( "this becomes:
\n" ); document.write( "1/5 >= x
\n" ); document.write( "to get x over to the left side of this equation you have to subtract x from both sides of this equation and to get 1/5 over to the right side of this equation you have to subtract 1/5 from both sides of this equation.
\n" ); document.write( "you get:
\n" ); document.write( "-x >= - (1/5)
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\n" ); document.write( "here's where the reversal of signs comes in.
\n" ); document.write( "if you multiply both sides of this equation by (-1) you get:
\n" ); document.write( "x <= (1/5)
\n" ); document.write( "note the inequality was reversed.
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\n" ); document.write( "the answer to this question is that if x <= 1/5, then the original equation of 16/5x >= 16 holds true, assuming i interpreted the original equation correctly.
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\n" ); document.write( "if x = 1/5 = .2, this equation becomes 16/1 >= 16 which is true.
\n" ); document.write( "if x = .3, this equation becomes 16/1.5 >= 16 which is false.
\n" ); document.write( "if x = .1, this equation becomes 16/.5 >= 16 which is true.
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\n" ); document.write( "answer is x <= (1/5)
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