document.write( "Question 657207: will you please help me solve this problem, I am not even sure how to start working it out, i cant even figure how to write an equation for this problem. please help: \"the sum of 8 times Sara's age and 5 times Ashley's age is 81. Ashley's is 9 years less than twice Sara's age. Find the age of each girl.\"
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #409794 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
Divide and conquer. Working one piece of the problem at a time, you need to read, interpret, and write as equations the pieces of information given.
\n" ); document.write( "
\n" ); document.write( "I would start by defining a variable, like this:
\n" ); document.write( "Let \"x\" be Sara's age (in years, of course).
\n" ); document.write( "
\n" ); document.write( "\"Ashley's is 9 years less than twice Sara's age.\"
\n" ); document.write( "Twice Sara's age would be \"2x\", and 9 years less than that
\n" ); document.write( "would be \"2x-9\".
\n" ); document.write( "So, Ashley's age is \"2x-9\".
\n" ); document.write( "
\n" ); document.write( "\"The sum of 8 times Sara's age and 5 times Ashley's age\" involves
\n" ); document.write( "8 times \"x\", which is \"8x\" and
\n" ); document.write( "5 times \"2x-9\", which is \"5%282x-9%29\".
\n" ); document.write( "The sum of those two numbers is 81, which means
\n" ); document.write( "\"highlight%288x%2B5%282x-9%29=81%29\".
\n" ); document.write( "That is your equation.
\n" ); document.write( "
\n" ); document.write( "Now, we solve:
\n" ); document.write( "First, we simplify the equation a bit.
\n" ); document.write( "To get rid of a parenthesis that is multiplied by a number (or an expression), we use the distributive property:
\n" ); document.write( "\"8x%2B5%282x-9%29=81\" --> \"8x%2B5%2A%282x%29%2B5%2A%28-9%29=81\" --> \"8x%2B10x-45=81\" --> \"18x-45=81\"
\n" ); document.write( "From there, we solve:
\n" ); document.write( "\"18x-45=81\" --> \"18x-45%2B45=81%2B45\" --> \"18x=126\" (adding 45 to both sides of the equal sign)
\n" ); document.write( "\"18x=126\" --> \"18x%2F18=126%2F18\" --> \"highlight%28x=7%29\" (dividing both sides by 18)
\n" ); document.write( "
\n" ); document.write( "Now we can translate the algebra back into words.
\n" ); document.write( "Sara is \"highlight%287%29\".
\n" ); document.write( "We said above that Ashley's age was \"2x-9\", so
\n" ); document.write( "Ashley's age is \"2%2A7-9=highlight%285%29\".
\n" ); document.write( "
\n" ); document.write( "The sum of 8 times Sara's age and 5 times Ashley's age is
\n" ); document.write( "\"8%2A7%2B5%2A5=56%2B25\" and \"56%2B25=81\".
\n" ); document.write( "
\n" ); document.write( "
\n" );