document.write( "Question 1196364: a12 = -45, a10 = -37; a1 = ? \n" ); document.write( "

Algebra.Com's Answer #829183 by Solver92311(821) $\"\"$ $\"About$

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\n" ); document.write( "\n" ); document.write( "First things first: When you want to indicate a subscript in plain text, use an underscore, thus: a_3 means

. If there is more than one character in the subscript, then enclose the subscript in curly braces, thus: a_{10} means

. You don't say so (and you most certainly should have) but I will assume an arithmetic sequence.\r
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is two terms of the sequence. The difference between the two terms given is

. Since that is the difference between terms 10 and 12, the common difference for the sequence must be half of that, or

. The number of terms from

. Then

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\n" ); document.write( "John
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\n" ); document.write( "My calculator said it, I believe it, that settles it
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