document.write( "Question 1173102: Manuel bought 6 candy bars and 3 sodas at the gas station for $8.40. Gary bought 3 candy bars and 4 sodas at the same gas station for $7.45. What is the price of one soda? \n" ); document.write( "

Algebra.Com's Answer #798298 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "The equations are\r\n" );
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document.write( "    6x + 3y = 840   cents\r\n" );
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document.write( "    3x + 4y = 745   cents\r\n" );
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document.write( "I will apply the determinant method (= the Cramers' rule) to find y, the soda's price.\r\n" );
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document.write( "    y =  = 130.\r\n" );
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document.write( "ANSWER.  The soda's price is $1.30.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "I never use a pocket calculator. \r
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\n" ); document.write( "\n" ); document.write( "I use Excel. I copy the formula into Excel and get the answer in one click (and with no error).\r
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\n" ); document.write( "\n" ); document.write( "            Side note. By the way, in engineering companies in US, where I worked for many years\r
\n" ); document.write( "\n" ); document.write( "            and where the engineers made thousands calculations every day, I did not see anyone
\n" ); document.write( "            who used pocket calculators - the engineers simply have no such a \"luxury\" to work so slowly.\r
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\n" ); document.write( "\n" ); document.write( "            All handle calculations were made in Excel. Honestly, working at their regular rate/charge/duties,
\n" ); document.write( "            the engineers simply HAVE NO TIME to lend a hand for a pocket calculator . . . \r
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\n" ); document.write( "\n" ); document.write( "            So, for me, calculators are comparable with the old typing machines, that all are now out
\n" ); document.write( "            of use just 20 or 30 years. // New generations of students just do not know what they were . . . \r
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\n" ); document.write( "\n" ); document.write( "If you have no Excel in your computer, you can use free of charge online calculator www.desmos.com \r
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\n" ); document.write( "\n" ); document.write( "In the same way as with Excel, you can copy (or type) the entire formula in this online calculator
\n" ); document.write( "and get the answer in one click.\r
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\n" ); document.write( "\n" ); document.write( "================\r
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\n" ); document.write( "\n" ); document.write( "On the Determinants' method for solving the systems of two linear equations in two unknowns see the lesson \r
\n" ); document.write( "\n" ); document.write( "    - Solution of the linear system of two equations in two unknowns using determinant \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic \"Systems of two linear equations in two unknowns\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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