document.write( "Question 808958: the current in a stream moves at a speed of 9 mph. a boat travels 4 mi upstream and 4 mi downstream in a total of 4 hours. what is the speed of the boat in still water? \n" ); document.write( "
Algebra.Com's Answer #487310 by TimothyLamb(4379)\"\" \"About 
You can put this solution on YOUR website!
s = d / t
\n" ); document.write( "t = d / s
\n" ); document.write( "---
\n" ); document.write( "4(miles)/(b + 9) + 4(miles)/(b - 9) = 4 hours
\n" ); document.write( "(1/4)(b + 9) + (1/4)(b - 9) = 1/4
\n" ); document.write( "(1/4)b + 9/4 + (1/4)b - 9/4 = 1/4
\n" ); document.write( "(1/2)b + = 1/4
\n" ); document.write( "b = 2/4
\n" ); document.write( "Answer:
\n" ); document.write( "Boat speed in still water is 0.5 mph
\n" ); document.write( "---
\n" ); document.write( "Solve and graph linear equations:
\n" ); document.write( "https://sooeet.com/math/linear-equation-solver.php
\n" ); document.write( "---
\n" ); document.write( "Solve quadratic equations, quadratic formula:
\n" ); document.write( "https://sooeet.com/math/quadratic-formula-solver.php
\n" ); document.write( "---
\n" ); document.write( "Convert fractions, decimals, and percents:
\n" ); document.write( "https://sooeet.com/math/fraction-decimal-percent.php
\n" ); document.write( "---
\n" ); document.write( "Calculate and graph the linear regression of any data set:
\n" ); document.write( "https://sooeet.com/math/linear-regression.php \n" ); document.write( "
\n" );