document.write( "Question 203386: use logarithms to solve each equation:\r
\n" ); document.write( "\n" ); document.write( "3(superscript x)= 5(superscript 5x-1)
\n" ); document.write( "

Algebra.Com's Answer #153450 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
3 (superscript x) is usually referred to as 3^x.
\n" ); document.write( "similarly 5 (superscript 5x-1) is usually referred to as 5^(5x-1).
\n" ); document.write( "^ is shift 6 on your keyboard.
\n" ); document.write( "-----
\n" ); document.write( "they should look like the following if I understood you correctly.\r
\n" ); document.write( "\n" ); document.write( "-----
\n" ); document.write( "as a general rule, if a = b, then log(a) = log(b), so if we let:
\n" ); document.write( "a = 3^x, and
\n" ); document.write( "b = 5^(5x-1), we get:
\n" ); document.write( "log(3^x) = log(5^(5x-1))
\n" ); document.write( "-----
\n" ); document.write( "by the rules of logarithms:
\n" ); document.write( "since we know, that log(3^x) is the same as x*log(3),
\n" ); document.write( "and we know that log(5^(5x-1)) is the same as (5x-1)*log(5), we get:
\n" ); document.write( "x*log(3) = (5x-1)*log(5)
\n" ); document.write( "-----
\n" ); document.write( "if we remove parentheses from the right side of the equation, we get:
\n" ); document.write( "x*log(3) = 5x*log(5) - log(5)
\n" ); document.write( "-----
\n" ); document.write( "if we add log(5) to both sides of this equation, and we subtract x*log(3) from both sides of this equation, we get:
\n" ); document.write( "log(5) = 5x*log(5) - x*log(3)
\n" ); document.write( "-----
\n" ); document.write( "if we separate the common factor x from the right side of the equation, we get:
\n" ); document.write( "log(5) = x*(5*log(5) - log(3))
\n" ); document.write( "which looks like this:\r
\n" ); document.write( "\n" ); document.write( "if we divide both sides of the equation by (5*log(5) - log(3)), we get:
\n" ); document.write( "x = log(5) / (5*log(5) - log(3))
\n" ); document.write( "which looks like this:\r
\n" ); document.write( "\n" ); document.write( "-----
\n" ); document.write( "now it's just a matter of finding log(5) and log(3) on the calculator and substituting in the equation to solve for x.
\n" ); document.write( "-----
\n" ); document.write( "since log(5) = .698970004
\n" ); document.write( "and log(3) = .477121255
\n" ); document.write( "we get:
\n" ); document.write( "x = .698970004 / (5*(.698970004) - .477121255)
\n" ); document.write( "which becomes:
\n" ); document.write( "x = .698970004 / 3.017728767
\n" ); document.write( "which becomes:
\n" ); document.write( "x = .231621215
\n" ); document.write( "-----
\n" ); document.write( "3^x = 3^(.231621215) = 1.289767428
\n" ); document.write( "and
\n" ); document.write( "5^(5x-1) = 5^(5*(.231621215) - 1)
\n" ); document.write( "which becomes:
\n" ); document.write( "5^(5x-1) = 5^(.158106076)
\n" ); document.write( "which becomes:
\n" ); document.write( "5^(5x-1) = 1.289767428
\n" ); document.write( "which means that:
\n" ); document.write( "3^x = 5^(5x-1)
\n" ); document.write( "because they both = 1.289767428
\n" ); document.write( "which means that the value of x is good, and your answer is:
\n" ); document.write( "x = .231621215
\n" ); document.write( "
\n" ); document.write( "
\n" );