document.write( "Question 360825: I have been trying to help my 8th grade daughter with her Algebra 1 homework. We have spent countless hours trying to figure this one out at her grade level. \r
\n" ); document.write( "\n" ); document.write( "The teacher is asking for an equation or rule for the following:\r
\n" ); document.write( "\n" ); document.write( "x values: 1, 10, 19, 28
\n" ); document.write( "y values: 6, 2, -2, -6
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\n" ); document.write( "(we know that the x values increase by 9)
\n" ); document.write( "(we know that the y values decrease by 4)\r
\n" ); document.write( "\n" ); document.write( "Please help us with this, trying to figure out every combination of -4/9 ??? or something. We need a rule or equation. THANK YOU SO MUCH \n" ); document.write( "

Algebra.Com's Answer #257470 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!


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document.write( "Hi, 
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document.write( "*Note: one may 'graph' the line by plotting the points and drawing the line thru them
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document.write( "Knowing that the x values increase by 9 as the y values decrease by 4
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document.write( "this discovery has led to the 'slope' of the line is (-4/9) 
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document.write( "Note: the general slope-intecept form of an equation of a line is:
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document.write( "y = mx + b  where m is the slope and b is the y value where the line crosses the y-axis
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document.write( "If you were looking for an equation of the line:
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document.write( "y = (-4/9)x + b
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document.write( "subsituting one of the ordered pairs to solve for b
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document.write( "(1,6)
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document.write( "6 = (-4/9)*1 + b
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document.write( "6 + 4/9) = b
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document.write( "58/9= b
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document.write( "y = (-4/9)x + 58/9  would be the equation of the line, 
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document.write( "which could also be written in standard form by mulitplying each side of the equation by 9
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document.write( "4x + 9y = 58
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