document.write( "Question 1065837: An investment is worth $3118 in 1993. By 1998 it has grown to $3748. Let y be the value of the investment in the year x, where x=0 represents 1993. Write a linear equation that models the value of the investment in the year x. \n" ); document.write( "
Algebra.Com's Answer #681011 by Boreal(15235)\"\" \"About 
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3798=3118(1+r)^n
\n" ); document.write( "This is the formula for annual rate of increase over n years.
\n" ); document.write( "Here, n=5
\n" ); document.write( "3798=3118(1+r)^5
\n" ); document.write( "1.2181 (don't round in calculations, however)=(1+r)^5
\n" ); document.write( "logs of both sides
\n" ); document.write( "log (1.2181)=5 log (1+r)
\n" ); document.write( "divide by 5 both sides
\n" ); document.write( "10 to the power on both sides
\n" ); document.write( "1.0402=1+r
\n" ); document.write( "subtract 1
\n" ); document.write( "r=0.0402 or 4%.
\n" ); document.write( "check
\n" ); document.write( "1.04^5=1.2167
\n" ); document.write( "3118*1.2167=3794, which is the same given the rounding.\r
\n" ); document.write( "\n" ); document.write( "I could expand (1+r)^5, bu that is not linear but a 5th power equation.
\n" ); document.write( "If this is not what is desired, please resubmit. The above equation is not linear, but accumulation of interest is not linear.\r
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