document.write( "Question 1151480: Smart student learning center charges students a registration fee of $25 plus an hourly rate of $30 for after school tutoring. Brilliant learning center charges students for after school tutoring based on the table below :
\n" ); document.write( " Brilliant student learning center
\n" ); document.write( " Hours of tutoring (x) Total cost (y)
\n" ); document.write( " 1 $45
\n" ); document.write( " 3 $115
\n" ); document.write( " 5 $185
\n" ); document.write( " 7 $255
\n" ); document.write( "If a student needs 4 hours of tutoring, which statement is true?
\n" ); document.write( "A. Smart student learning center charges$5 more than Brillant student learning center.
\n" ); document.write( "B.
\n" ); document.write( "Brilliant student learning center charges $5 more than Smart student learning center.
\n" ); document.write( "C.Smart student learning center charges #35 more than Brilliant student learning center.
\n" ); document.write( "D. Brillant student learning center charges $35 more than Smart student learning center.
\n" ); document.write( "

Algebra.Com's Answer #773243 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "x = number of hours of tutoring
\n" ); document.write( "y = total cost\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Smart student center learning, which I'll just abbreviate to \"Company S\", charges a registration fee of $25 plus an hourly rate of $30. This means the equation for Company S is
\n" ); document.write( "y = 30x+25\r
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\n" ); document.write( "\n" ); document.write( "Note how this equation is in the form y = mx+b
\n" ); document.write( "m = slope = 30
\n" ); document.write( "b = y intercept = 25
\n" ); document.write( "The slope tells us how much y goes up each time x increases by 1 (ie, for each increase of 1 hour, the cost goes up by $30)
\n" ); document.write( "The y intercept is the starting cost, or the cost if you have x = 0 hours of tutoring.\r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I'll abbreviate \"Brilliant learning center\" as \"Company B\". This company has the following table of x,y values.
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xy
145
3115
5185
7255
\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Pick two points from that table, say the first two rows
\n" ); document.write( "Row1: (x1,y1) = (1, 45)
\n" ); document.write( "Row2: (x2,y2) = (3, 115)\r
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\n" ); document.write( "\n" ); document.write( "Compute the slope between those two points
\n" ); document.write( "m = (y2-y1)/(x2-x1)
\n" ); document.write( "m = (115-45)/(2)
\n" ); document.write( "m = 70/2
\n" ); document.write( "m = 35
\n" ); document.write( "The slope is 35, which means Company B charges $35 an hour.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Use any row of the table as the (x,y) value. I'll use row 1, so (x,y) = (1,45)
\n" ); document.write( "Plug those values, along with m = 35, into the form
\n" ); document.write( "y = mx+b
\n" ); document.write( "and solve for b\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = mx+b
\n" ); document.write( "45 = 35*1+b
\n" ); document.write( "45 = 35+b
\n" ); document.write( "45-35 = b
\n" ); document.write( "10 = b
\n" ); document.write( "b = 10
\n" ); document.write( "The starting cost for Company B is $10, i.e. this is the registration cost or the cost of having x = 0 hours of tutoring.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Overall the equation for Company B is
\n" ); document.write( "y = 35x+10\r
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\n" ); document.write( "\n" ); document.write( "----------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "To summarize so far:\r
\n" ); document.write( "\n" ); document.write( "y = 30x+25 is the cost equation for Company S
\n" ); document.write( "y = 35x+10 is the cost equation for Company B\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From here we plug x = 4 into each equation and simplify using PEMDAS\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Company S
\n" ); document.write( "y = 30*x+25
\n" ); document.write( "y = 30*4+25
\n" ); document.write( "y = 120+25
\n" ); document.write( "y = 145
\n" ); document.write( "Having x = 4 hours of tutoring at Company S will cost you y = 145 dollars.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Company B
\n" ); document.write( "y = 35*x+10
\n" ); document.write( "y = 35*4+10
\n" ); document.write( "y = 140+10
\n" ); document.write( "y = 150
\n" ); document.write( "Having x = 4 hours of tutoring at Company B will cost you y = 150 dollars.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We see the difference of the two companies is 150-145 = 5 dollars. So Company S is cheaper by $5. Or put another way, Company B is $5 more expensive.\r
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\n" ); document.write( "\n" ); document.write( "Final Answer:
\n" ); document.write( "B) Brilliant student learning center charges $5 more than Smart student learning center.
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