document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=174628>Question 174628</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9781567655568/algebrahomeworkh>Amsco's Preparing for the Regents Examination Mathematics B</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> 6) If 4^x = 2^y and 9^x-1 = 3^x+1, which of the following are the values of x and y?<BR>\n" );
document.write( "    (a) x = 2, y = 4 (b) x=3, y=6  (c) x=4, y=2  (d) x=6, y=3\r<BR>\n" );
document.write( "\n" );
document.write( "7)When David was born, his grandparents deposited $1,000 in a college account that promised 4 percent interest compounded annually for 18 years. Which of the following equations shows the worth of the account when David is 18?<BR>\n" );
document.write( "    (a) y = 18(4)($1,000)<BR>\n" );
document.write( "    (b) y = 18(0.04)($1,000)<BR>\n" );
document.write( "    (c) y = $1,000(0.04)^18<BR>\n" );
document.write( "    (d) y = $1,000(1.04)^18\r<BR>\n" );
document.write( "\n" );
document.write( "Show work thanks so much! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #129663 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=129663\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 6) If 4^x = 2^y and 9^x-1 = 3^x+1, which of the following are the values of x and y?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "In the 1st equation, we can write 4^x as 2^(2x), so we have<BR>\n" );
document.write( "2^(2x) = 2^y<BR>\n" );
document.write( "Therefore:<BR>\n" );
document.write( "2x = y<BR>\n" );
document.write( ":<BR>\n" );
document.write( "In the 2nd equation, the same:<BR>\n" );
document.write( "3^(2(x-1)) = 3^(x+1)<BR>\n" );
document.write( "therefore<BR>\n" );
document.write( "2(x-1) = x + 1<BR>\n" );
document.write( "2x - 2 = x + 1<BR>\n" );
document.write( "2x - x = 1 + 2<BR>\n" );
document.write( "x = 3<BR>\n" );
document.write( "2x = y, therefore<BR>\n" );
document.write( "y = 6<BR>\n" );
document.write( ":<BR>\n" );
document.write( ":<BR>\n" );
document.write( "7)When David was born, his grandparents deposited $1,000 in a college account that promised 4 percent interest compounded annually for 18 years. Which of the following equations shows the worth of the account when David is 18?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "The interest is added to the accumulated amt each year for 18 yrs, therefore:<BR>\n" );
document.write( "(d) 1000*(1.04)^18 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );