document.write( "Question 472326: Hello. I am having troubles with the problem -x^2-7x+30. Factoring trinomials. Write each factor in descending order. I'm not getting an answer, I don't know what would multiply to 30 and add to 7. \n" ); document.write( "
Algebra.Com's Answer #323842 by MathLover1(20850)\"\" \"About 
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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%2B-7%2Ax%2B30\", first we need to ask ourselves: What two numbers multiply to 30 and add to -7? Lets find out by listing all of the possible factors of 30
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\n" ); document.write( " Factors:
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\n" ); document.write( " 1,2,3,5,6,10,15,30,
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\n" ); document.write( " -1,-2,-3,-5,-6,-10,-15,-30,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 30.
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\n" ); document.write( " 1*30=30
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\n" ); document.write( " 2*15=30
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\n" ); document.write( " 3*10=30
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\n" ); document.write( " 5*6=30
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\n" ); document.write( " (-1)*(-30)=30
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\n" ); document.write( " (-2)*(-15)=30
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\n" ); document.write( " (-3)*(-10)=30
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\n" ); document.write( " (-5)*(-6)=30
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\n" ); document.write( " note: remember two negative numbers multiplied together make a positive number
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\n" ); document.write( " Now which of these pairs add to -7? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -7
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First Number|Second Number|Sum
1|30|1+30=31
2|15|2+15=17
3|10|3+10=13
5|6|5+6=11
-1|-30|-1+(-30)=-31
-2|-15|-2+(-15)=-17
-3|-10|-3+(-10)=-13
-5|-6|-5+(-6)=-11
\r\n" ); document.write( " \r\n" ); document.write( " None of these factors add to -7. So this quadratic cannot be factored. In order to solve for x, we need to use the quadratic formula.\n" ); document.write( "
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