document.write( "Question 72913This question is from textbook mcgougal littell algebra 2
\n" ); document.write( ": Write an exponential function of the form y=ab^x whose graph passes through the given points.\r
\n" ); document.write( "\n" ); document.write( "17. (1,4),(2,12) \n" ); document.write( "

Algebra.Com's Answer #52139 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
Plug in both x and y into the general form
\n" ); document.write( " $\"y=ab%5Ex\"$
\n" ); document.write( " $\"4=ab%5E1\"$ Plug in (1,4)
\n" ); document.write( " $\"b=4%2Fa\"$ solve for b
\n" ); document.write( " $\"12=ab%5E2\"$ Plug in point (2,12)
\n" ); document.write( "Now plug in b=4/a into b of $\"12=ab%5E2\"$
\n" ); document.write( " $\"12=a%284%2Fa%29%5E2\"$
\n" ); document.write( " $\"12=a%2816%2Fa%5E2%29\"$
\n" ); document.write( " $\"12=16%2Fa\"$ Solve for a
\n" ); document.write( " $\"a=16%2F12\"$
\n" ); document.write( " $\"a=4%2F3\"$ Plug this into $\"y=ab%5Ex\"$ with any point also
\n" ); document.write( " $\"4=%284%2F3%29b%5E1\"$ Solve for b
\n" ); document.write( " $\"4%283%2F4%29=b\"$
\n" ); document.write( " $\"b=3\"$
\n" ); document.write( "So the equation is
\n" ); document.write( " $\"y=%284%2F3%29%283%29%5Ex\"$
\n" ); document.write( "Check:
\n" ); document.write( "Plug in x=1, you should get y=4
\n" ); document.write( " $\"y=%284%2F3%29%283%29%5E1\"$
\n" ); document.write( " $\"y=4\"$ works
\n" ); document.write( "

\n" ); document.write( "Plug in x=2, you should get y=12
\n" ); document.write( " $\"y=%284%2F3%29%283%29%5E2\"$
\n" ); document.write( " $\"y=%284%2A9%29%2F3\"$
\n" ); document.write( " $\"y=12\"$ works\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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