document.write( "Question 1100219: Problem 1: When twice the second number is subtracted from the first number, the result is -18. The square of the sum of the first number and 2 is equal to the second number minus 3.\r
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document.write( "Problem 2: Twice the square of the first number minus the second number is -3. The square of the sum of the first number and 5 is equal to the second number minus 2.\r
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document.write( "Please include \"let statements\" and equations. Thank you! \n" );
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Algebra.Com's Answer #714722 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Problem 1: \n" ); document.write( "let a = the first number \n" ); document.write( "let b = the second number \n" ); document.write( ": \n" ); document.write( "Write an equation for each statement \n" ); document.write( "\"When twice the second number is subtracted from the first number, the result is -18.\" \n" ); document.write( "a - 2b = -18 \n" ); document.write( "rearrange for substitution in the 2nd equation \n" ); document.write( "-2b = -a - 18 \n" ); document.write( "multiply by -1 \n" ); document.write( "2b = a + 18 \n" ); document.write( "b = \n" ); document.write( ": \n" ); document.write( "\"The square of the sum of the first number and 2 is equal to the second number minus 3.\" \n" ); document.write( "(a+2)^2 = b - 3 \n" ); document.write( "FOIL (a+2)(a+2) \n" ); document.write( "a^2 + 4a + 4 = b - 3 \n" ); document.write( "replace b with \n" ); document.write( "a^2 + 4a + 4 = \n" ); document.write( "get rid of the fraction, multiply by 2 \n" ); document.write( "2a^2 + 8a + 8 = a + 18 - 6 \n" ); document.write( "2a^2 + 8a + 8 = a + 12 \n" ); document.write( "2a^2 + 8a - a + 8 - 12 = 0 \n" ); document.write( "2a^2 + 7a - 4 = 0 \n" ); document.write( "Assuming they are using integers, it must factor \n" ); document.write( "(2a-1)(a+4) = 0 \n" ); document.write( "two solutions \n" ); document.write( "a = 1/2 \n" ); document.write( "and \n" ); document.write( "a = -4 the integer solution is what we want here \n" ); document.write( ": \n" ); document.write( "find b using the 1st equation when a = -4 \n" ); document.write( "-4 - 2b = -18 \n" ); document.write( "multiply by -1 \n" ); document.write( "4 + 2b = 18 \n" ); document.write( "2b = 18 - 4 \n" ); document.write( "2b = 14 \n" ); document.write( "b = 7 \n" ); document.write( ": \n" ); document.write( "1st number is -4, 2nd number is +7 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "see if that checks out in the 2nd equation \n" ); document.write( "(-4+2)^2 = 7 - 3 \n" ); document.write( "-2^2 = 4 \n" ); document.write( "4 = 4 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( " Problem 2: Much like the first problem \n" ); document.write( "Twice the square of the first number minus the second number is -3. \n" ); document.write( "2a^2 - b = -3 \n" ); document.write( "-b = -2a^2 - 3 \n" ); document.write( "b = 2a^2 + 3 \n" ); document.write( ": \n" ); document.write( " The square of the sum of the first number and 5 is equal to the second number minus 2. \n" ); document.write( "(a+5)^2 = b - 2 \n" ); document.write( "FOIL, Replace b with 2a^2 + 3 \n" ); document.write( "a^2 + 10a + 25 = 2a^2 + 3 - 2 \n" ); document.write( "a^2 + 10a + 25 = 2a^2 + 1 \n" ); document.write( "combine on the right \n" ); document.write( "0 = 2a^2 - a^2 - 10a - 25 + 1 \n" ); document.write( "0 = a^2 - 10a - 24 \n" ); document.write( "(a - 12)(a + 2) = 0 \n" ); document.write( "Two solutions \n" ); document.write( "a = 12 \n" ); document.write( "and \n" ); document.write( "a = -2 \n" ); document.write( "Find b when a = 12 \n" ); document.write( "b = 2(12^2) + 3 \n" ); document.write( "b = 2(144) + 3 \n" ); document.write( "b = 289 \n" ); document.write( "See if that works in the 2nd equation \n" ); document.write( "(12 + 5)^2 = 289 - 2 \n" ); document.write( "17^2 = 287 \n" ); document.write( ": \n" ); document.write( "Why don't you find b when a = -2 and check that out\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |