document.write( "Question 57649: If a contractor charges 30 for 2hours work and charges 94 for 4 hours of work what would he charge for 8 hours of work? \n" ); document.write( "
Algebra.Com's Answer #39367 by tutorcecilia(2152)\"\" \"About 
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Since the amount of money charged increases with the amount of time spent working, there is a linear relationship between time and money. One type of equation you could use is the slope-intercept equation of a line (y=mx+b)
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\n" ); document.write( "First find the slope of the line by using the two points that are given:
\n" ); document.write( "(2, 30) and (4, 94)
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\n" ); document.write( "Slope =m=(y-y2)/(x-x2) [Formula for the slope of a line]
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\n" ); document.write( "m=(94-30)/(4-2)=64/2=32 [Plug-in the values of the two points]
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\n" ); document.write( "y=mx+b
\n" ); document.write( "30=(32)(2)+b [Plug-in the values for the slope and one point]
\n" ); document.write( "30=65+b [Solve for b]
\n" ); document.write( "-65+30=b
\n" ); document.write( "-34=b
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\n" ); document.write( "y=mx+b [Plug-in the values for the slope and the y-intercept (b)]
\n" ); document.write( "y=32x-34 [Equation of the line]
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\n" ); document.write( "To find any point on the line, plug-in the known variable and solve for the unknown variable:
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\n" ); document.write( "Find (8, y)
\n" ); document.write( "y=(32)(8)-34
\n" ); document.write( "y=222
\n" ); document.write( "So, when 8 hours are worked, the charge is $222 \n" ); document.write( "
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