document.write( "Question 76887This question is from textbook Prealgebra and Introductory Algebra
\n" ); document.write( ": The perimeter of a triangle is 85 inches. The sides are: 2x, 2x+5, and X squared + 3 Find the legths of the sides.\r
\n" ); document.write( "\n" ); document.write( "I though of putting them all together and then factoring, but it wasn't working out. If someone could help me I would really appreciate it.\r
\n" ); document.write( "\n" ); document.write( "Thank you very much for your time.
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Algebra.Com's Answer #55118 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
If we add all of the sides we get the perimeter, so\r
\n" ); document.write( "\n" ); document.write( "\"%282x%29%2B%282x%2B5%29%2B%28x%5E2%2B3%29=85\"\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B4x%2B8-85=0\" Combine like terms and get all terms to one side\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B4x-77=0\"\r
\n" ); document.write( "\n" ); document.write( "Now we can factor the left side\r
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Solved by pluggable solver: Factoring Quadratics with a leading coefficient of 1 (a=1)
In order to factor \"1%2Ax%5E2%2B4%2Ax%2B-77\", first we need to ask ourselves: What two numbers multiply to -77 and add to 4? Lets find out by listing all of the possible factors of -77
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\n" ); document.write( " Factors:
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\n" ); document.write( " 1,7,11,77,
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\n" ); document.write( " -1,-7,-11,-77,List the negative factors as well. This will allow us to find all possible combinations
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\n" ); document.write( " These factors pair up to multiply to -77.
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\n" ); document.write( " (-1)*(77)=-77
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\n" ); document.write( " (-7)*(11)=-77
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\n" ); document.write( " Now which of these pairs add to 4? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 4
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First Number|Second Number|Sum
1|-77|1+(-77)=-76
7|-11|7+(-11)=-4
-1|77|(-1)+77=76
-7|11|(-7)+11=4
We can see from the table that -7 and 11 add to 4.So the two numbers that multiply to -77 and add to 4 are: -7 and 11\r\n" ); document.write( " \r\n" ); document.write( " Now we substitute these numbers into a and b of the general equation of a product of linear factors which is:\r\n" ); document.write( " \r\n" ); document.write( " \"%28x%2Ba%29%28x%2Bb%29\"substitute a=-7 and b=11\r\n" ); document.write( " \r\n" ); document.write( " So the equation becomes:\r\n" ); document.write( " \r\n" ); document.write( " (x-7)(x+11)\r\n" ); document.write( " \r\n" ); document.write( " Notice that if we foil (x-7)(x+11) we get the quadratic \"1%2Ax%5E2%2B4%2Ax%2B-77\" again\n" ); document.write( "

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\n" ); document.write( "\n" ); document.write( "So the quadratic \"x%5E2%2B4x-77=0\" factors to \"%28x-7%29%28x%2B11%29=0\"\r
\n" ); document.write( "\n" ); document.write( "Now set each term equal to zero\r
\n" ); document.write( "\n" ); document.write( "\"x-7=0\"
\n" ); document.write( "\"x=7\"
\n" ); document.write( "\"x%2B11=0\"
\n" ); document.write( "\"x=-11\" This answer doesn't make any sense (a negative length doesn't work)\r
\n" ); document.write( "\n" ); document.write( "So our answer is 7
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\n" ); document.write( "Check:
\n" ); document.write( "\"%282%287%29%29%2B%282%287%29%2B5%29%2B%28%287%29%5E2%2B3%29=85\"
\n" ); document.write( "\"%2814%29%2B%2814%2B5%29%2B%2849%2B3%29=85\"
\n" ); document.write( "\"%2814%29%2B%2819%29%2B%2852%29=85\"
\n" ); document.write( "\"85=85\" works \n" ); document.write( "

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