document.write( "Question 240762: Solve for b:\r
\n" );
document.write( "\n" );
document.write( "logb8=-3 \n" );
document.write( "
Algebra.Com's Answer #176374 by jsmallt9(3759) ![]() You can put this solution on YOUR website! When the variable is in the argument or the base of a logarithm, you solve for that variable by rewriting the equation in exponential form. This is done by using the fact that \n" ); document.write( "Rewriting your equation in exponential form we get: \n" ); document.write( " \n" ); document.write( "Now we have an equation we can solve. There are several ways we could solve this. One would be to raise both sides to the -1/3 power. (You'll see wht when we're done) \n" ); document.write( " \n" ); document.write( "which results in: \n" ); document.write( " \n" ); document.write( "We have been trying to solve for b and, as you can see, we have been able to do this in one step (raising to the -1/3 power). All that is left is to simpilfy the right side. To do this by hand it helps to factor the exponent: \n" ); document.write( " \n" ); document.write( "or \n" ); document.write( " \n" ); document.write( "Since 1/3 as an exponent means \"cube root of\" and the cube root of 8 is 2: \n" ); document.write( " \n" ); document.write( "Since -1 as an exponent means \"reciprocal of\" and the reciprocal of 2 is 1/2: \n" ); document.write( " |