document.write( "Question 155228: kindly solve these problems for me:
\n" ); document.write( "1. Charles and Melanie are 100 km apart and are driving at constant speeds. If they drive toward each other, they will meet in 1 hr. If they drive in the same direction, he will overtake her in 5 hr. Find their speeds.
\n" ); document.write( "2. Wayne invested part of his money at 8% and the rest at 6%. The income from both investments totaled $2,000. If he interchanged his investments, his income would increase by $340. How much did he have in each investment?
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Algebra.Com's Answer #114351 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
1. Charles and Melanie are 100 km apart and are driving at constant speeds.
\n" ); document.write( " If they drive toward each other, they will meet in 1 hr. If they drive in
\n" ); document.write( " the same direction, he will overtake her in 5 hr. Find their speeds.
\n" ); document.write( ";
\n" ); document.write( "Let x = C's speed
\n" ); document.write( "Let y = M's speed
\n" ); document.write( ":
\n" ); document.write( "When they are driving towards each other, their speeds are additive:
\n" ); document.write( "Write a distance equation, Dist = time * speed
\n" ); document.write( "1(x+y) = 100
\n" ); document.write( "x + y = 100
\n" ); document.write( "or
\n" ); document.write( "y = (100-x)
\n" ); document.write( ":
\n" ); document.write( "Write another distance equation, when they go the same direction.
\n" ); document.write( "C has to travel has to travel 100 further than M in the same time (5 hrs)\r
\n" ); document.write( "\n" ); document.write( "5x - 100 = 5y
\n" ); document.write( "Replace y with (100-x)
\n" ); document.write( "5x - 100 = 5(100-x)
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\n" ); document.write( "5x - 100 = 500 - 5x
\n" ); document.write( ":
\n" ); document.write( "5x + 5x = 500 + 100
\n" ); document.write( ":
\n" ); document.write( "10x = 600
\n" ); document.write( ":
\n" ); document.write( "x = 60 km/hr is C's speed
\n" ); document.write( "Find M's speed
\n" ); document.write( "y = 100 - 60
\n" ); document.write( "y = 40 km/hr is M's speed
\n" ); document.write( ":
\n" ); document.write( "Check solutions using the distance
\n" ); document.write( "5*60 = 300 km
\n" ); document.write( "5*40 = 200 km
\n" ); document.write( "--------------
\n" ); document.write( "diff = 100 km
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\n" ); document.write( ":
\n" ); document.write( "2. Wayne invested part of his money at 8% and the rest at 6%. The income from
\n" ); document.write( "both investments totaled $2,000. If he interchanged his investments, his
\n" ); document.write( " income would increase by $340. How much did he have in each investment?
\n" ); document.write( ":
\n" ); document.write( "Originally: x = amt invested at 8% and y = amt invested at 6%
\n" ); document.write( ":
\n" ); document.write( ".08x + .06y = 2000; original income equation
\n" ); document.write( ".06x + .08y = 2340; switched income equation
\n" ); document.write( ":
\n" ); document.write( "Multiply the 1st equation by 8, and the 2nd equation by 6; results
\n" ); document.write( ".64x +.48y = 16000
\n" ); document.write( ".36x + 48y = 14040
\n" ); document.write( "----------------------subtraction eliminates y, find x
\n" ); document.write( ".28x + 0y = 1960
\n" ); document.write( ":
\n" ); document.write( "x = \"1960%2F28\"
\n" ); document.write( "x = $7,000 originally invested at 8%
\n" ); document.write( ":
\n" ); document.write( "Find y:
\n" ); document.write( ".08(7000) + .06y = 2000
\n" ); document.write( "560 + .06y = 2000
\n" ); document.write( ".06y = 2000 - 560
\n" ); document.write( ".06y = 1440
\n" ); document.write( "y = \"1440%2F.06\"
\n" ); document.write( "y = $24,000
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solution by switching the investments
\n" ); document.write( ".08(24000) + .06(7000) =
\n" ); document.write( "1920 + 420 = 2340; confirms our solutions
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\n" ); document.write( ":
\n" ); document.write( "Do you have any questions about either of these? did you understand what we did?\r
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