document.write( "Question 1190037: Convert the following decimal numbers to into binary format\r
\n" ); document.write( "\n" ); document.write( "a. 15\r
\n" ); document.write( "\n" ); document.write( "b. 210\r
\n" ); document.write( "\n" ); document.write( "c. 119\r
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\n" ); document.write( "\n" ); document.write( "Can you please explain me this homework question step-by-step? Thank you!
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Algebra.Com's Answer #821585 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "The other tutors have great answers. Here's an alternative approach\r
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\n" ); document.write( "Part (a)\r
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\n" ); document.write( "\n" ); document.write( "We'll need the powers of 2
\n" ); document.write( "1,2,4,8,16,32,...\r
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\n" ); document.write( "\n" ); document.write( "Start with 15. Then subtract off the largest possible power of 2. In this case, we can subtract off 8
\n" ); document.write( "15-8 = 7
\n" ); document.write( "Then subtract off 4
\n" ); document.write( "7-4 = 3
\n" ); document.write( "Subtract off 2
\n" ); document.write( "3-2 = 1
\n" ); document.write( "Then subtract off 1
\n" ); document.write( "1-1 = 0\r
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\n" ); document.write( "\n" ); document.write( "Work that process in reverse and we get
\n" ); document.write( "15 = 1+2+4+8
\n" ); document.write( "Showing that
\n" ); document.write( "15 base 10 = 1111 base 2
\n" ); document.write( "Each '1' is like a lightswitch that turns on the powers of 2 we're summing. \r
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\n" ); document.write( "Part (b)\r
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\n" ); document.write( "\n" ); document.write( "We could use the previous idea but here's another way\r
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\n" ); document.write( "\n" ); document.write( "15 base 10 = 1111 base 2
\n" ); document.write( "2 base 10 = 0010 base 2\r
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\n" ); document.write( "\n" ); document.write( "13 base 10 = (15 base 10) - (2 base 10)
\n" ); document.write( "13 base 10 = (1111 base 2) - (0010 base 10)
\n" ); document.write( "13 base 10 = 1101 base 2\r
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\n" ); document.write( "\n" ); document.write( "210 base 10 = 208 base 10 + 2 base 10
\n" ); document.write( "210 base 10 = (16*13) base 10 + 2 base 10
\n" ); document.write( "210 base 10 = 1101 0000 base 2 + 10 base 2 ... see note below
\n" ); document.write( "210 base 10 = 1101 0010 base 2\r
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\n" ); document.write( "\n" ); document.write( "note: multiplying by 16 in base 2 is as easy as sticking four zeros at the far right end of the number
\n" ); document.write( "It's not a coincidence that 2^4 = 16.\r
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\n" ); document.write( "Part (c)\r
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\n" ); document.write( "\n" ); document.write( "Like with part (b), I'll try to break this number into parts of 16. Or at least, try to get close to such multiples of 16.\r
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\n" ); document.write( "\n" ); document.write( "As Alan alluded to, it's probably better to work with hexadecimal (base 16) since the numbers in binary are very long strings of 1's and 0's. It's easy to get lost.\r
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\n" ); document.write( "\n" ); document.write( "7 base 10 = 0111 base 2\r
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\n" ); document.write( "\n" ); document.write( "119 base 10 = 112 base 10 + 7 base 10
\n" ); document.write( "119 base 10 = (16*7) base 10 + 7 base 10
\n" ); document.write( "119 base 10 = 0111 0000 base 2 + 0111 base 2
\n" ); document.write( "119 base 10 = 0111 0111 base 2\r
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\n" ); document.write( "\n" ); document.write( "If you are more familiar with the other methods presented by the other tutors, then ignore my post entirely. \r
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\n" ); document.write( "\n" ); document.write( "I recommend the use of any online calculators that quickly convert from binary to decimal (and vice versa) to check your work. Keep in mind that it's not a good idea to rely entirely on the calculator because your teacher will want you to show your work (or thought process). The calculator is merely a tool to see if you have the right answer or not.
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