document.write( "Question 1011285: Why are + signs sometimes left out of problems. When I do -3(2t+6) I get -6t+(-18). But my book and calculators both say -3(2t+6)=-6t-18. What happened to the + between the t and the 6? \n" ); document.write( "

Algebra.Com's Answer #626901 by josgarithmetic(39618) $\"\"$ $\"About$

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Why? If A NUMBER has no sign on or in front of it, the sign IS ASSUMED to be PLUS for POSITIVE; Not that the number is positive, but that the SIGN is positive. If a negative sign is intended, then this negative sign is NEEDED; otherwise the PLUS sign is assumed.\r
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\n" ); document.write( "\n" ); document.write( "You first learn about numbers when you learn to count and learn to add and subtract. At that stage, you would not understand positive and negative numbers. All numbers have no sense with signs of PLUS OR MINUS; you only are learning about Whole Numbers, and the four basic arithmetic operations.\r
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\n" ); document.write( "\n" ); document.write( "A few years later, you learn about extending a number line to BOTH sides of zero; so you have numbers increasing toward the right which become the POSITIVE numbers, and you have numbers decreasing toward the left which become the NEGATIVE numbers. You also are taught how to understand and perform both addition and subtraction USING the number line and during this learning is when you develop your understanding and skill to sort through Additions and Subtractions of signed numbers.\r
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\n" ); document.write( "\n" ); document.write( "The way to make some progress with this is to study Introductory or Elementary Algebra. \n" ); document.write( "

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