document.write( "Question 76446This question is from textbook Beginning Algebra
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document.write( ": I need help on page #575 on question #20. I need to solve the roots of each quadratic equation using the factoring method, and place the equation in standard form before factoring:\r
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document.write( "X^2=10x-24\r
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document.write( "Thanks for your time. =)\r
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Algebra.Com's Answer #54842 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! Given: \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Task: Arrange in standard form and solve for x by factoring \n" ); document.write( ". \n" ); document.write( "The standard form of a quadratic equation is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "The key features of this form are: \n" ); document.write( "(1) all the terms are on the left side and zero is on the right side and \n" ); document.write( "(2) the terms on the left side are arranged in descending powers of x. So the first term \n" ); document.write( "contains \n" ); document.write( ". \n" ); document.write( "To get the given equation in standard form we need to eliminate the two terms on the right \n" ); document.write( "side by subtracting 10x - 24. But if you subtract 10x - 24 from the right side, you must \n" ); document.write( "also subtract 10x - 24 from the left side to keep the equation in balance. When you subtract \n" ); document.write( "10x - 24 from both sides the equation becomes: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "The rule to remove a set of parentheses preceded by a minus sign you remove the minus sign \n" ); document.write( "and the parentheses but you need to change the sign of each term in the parentheses. \n" ); document.write( "Applying this rule to the parentheses on the left side you get: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Since we already have the terms arranged in descending powers of x we have things in \n" ); document.write( "the standard form. Therefore we have met the first requirement of the problem. Now we have \n" ); document.write( "to solve for values of x that will make the left side of the equation equal zero. \n" ); document.write( ". \n" ); document.write( "Since the multiplier of the \n" ); document.write( ". \n" ); document.write( "(x __ ___)*(x __ ___) \n" ); document.write( ". \n" ); document.write( "where the underlines in each set of parentheses represent a missing sign and a missing number. \n" ); document.write( ". \n" ); document.write( "The missing numbers in the two sets of parentheses must be factors of 24, because when \n" ); document.write( "they are multiplied together they must equal +24. Because the product must be positive \n" ); document.write( "the two numbers must both be positive or both be negative. If one was positive and one \n" ); document.write( "was negative, their product would be -24, and we need it to be +24. Now we look at the \n" ); document.write( "middle term on the left side. Its multiplier is -10. We know that the two factors \n" ); document.write( "of 24 that we use must have a product of +24 and a sum of -10. From this we can tell that \n" ); document.write( "the factors must both be negative (so their product is +24 and their sum is -10). Now \n" ); document.write( "we know that the missing factors of 24 must add to be -10. The factors of 24 are: \n" ); document.write( "(24 and 1), (12 and 2), (8 and 3), and (6 and 4). The only set of factors that adds up \n" ); document.write( "to 10 is 6 and 4. And both must be negative so they add to be -10 and multiply to be +24. \n" ); document.write( ". \n" ); document.write( "So we now know that the factors of the left side are: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "and the equation, therefore, is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Note that this equation will be true if either of the factors is equal to zero, because \n" ); document.write( "multiplying the left side by 0 will make it equal to the right side. \n" ); document.write( ". \n" ); document.write( "So we know that either \n" ); document.write( "these two equations and you get \n" ); document.write( "will make equal the left and right sides of the original equation you were given. \n" ); document.write( ". \n" ); document.write( "Try it for x = 4. The original equation becomes: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "This expands to become: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "which simplifies to \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "This verifies that x = 4 is a correct solution. You can do the same sort of checking \n" ); document.write( "for x = 6. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand the problem a little better and helps you to understand \n" ); document.write( "the method you can use to factor a quadratic if the multiplier of the \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |