document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=844963>Question 844963</A>: <I><SPAN STYLE=\"word-break: break-all;\"> acid 'a' is 30% acid. acid 'b' is 70% acid. How much of each should be mixed to make 40 ml of a 45% acid?. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #509033 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=509033\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x = the number of ml of solution A.<BR>\n" );
document.write( "y = the number of ml of solution B.<BR>\n" );
document.write( ".30x = the number of ml of acid in solution A.<BR>\n" );
document.write( ".70y = the number of ml of acid in solution B.<BR>\n" );
document.write( "the equations you need to solve are:<BR>\n" );
document.write( "x + y = 40<BR>\n" );
document.write( ".30x + .70y = .45 * 40<BR>\n" );
document.write( "the first equations tells you the total ml of each solution.<BR>\n" );
document.write( "the second equation tells you the ml of acid in each solution.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "simplify these equations to get:<BR>\n" );
document.write( "x + y = 40<BR>\n" );
document.write( ".30x + .70y = 18\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "solve for y in the first equation to get y = 40-x<BR>\n" );
document.write( "substitute 40-x for y in the second equation to get:<BR>\n" );
document.write( ".30x + .70(40-x) = 18<BR>\n" );
document.write( "simplify to get:<BR>\n" );
document.write( ".30x + 28 - .7x = 18<BR>\n" );
document.write( "combine like terms to get:<BR>\n" );
document.write( "-.4x + 28 = 18<BR>\n" );
document.write( "subtract 28 from both sides of this equation to get:<BR>\n" );
document.write( "-.4x = 18 - 28<BR>\n" );
document.write( "simplify to get:<BR>\n" );
document.write( "-.4x = -10<BR>\n" );
document.write( "divide both sides of this equation by -.4 to get:<BR>\n" );
document.write( "x = -10 / -.4 which result in:<BR>\n" );
document.write( "x = 25<BR>\n" );
document.write( "since x + y = 40, then:<BR>\n" );
document.write( "y = 15 because  25 + 15 = 40\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "you have:<BR>\n" );
document.write( "x = 25ml<BR>\n" );
document.write( "y = 15 ml\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the amount of acid in 25 ml of solution A is equal to .30 * 25 = 7.5 ml.<BR>\n" );
document.write( "the amount of acid in 15 ml of solution B is equal to .70 * 15 = 10.5 ml.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "total amount of acid in 40 ml of the mixture that contains 25 ml of solution A and 15 ml of solution B is 7.5 + 10.5 = 18 ml.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "18 / 40 is equal to .45 which is equal to 45%, so the numbers are good.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );