document.write( "Question 444573: What is the slope - intercept for a line that passes through (-4,-3) and (-6,7)Show the work. \n" ); document.write( "

Algebra.Com's Answer #306416 by oberobic(2304) $\"\"$ $\"About$

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Here we are given the two points that define a line: (-4,-3) and (-6,7).
\n" ); document.write( "We know the slope = change in y divided by the change in x.
\n" ); document.write( "That is often called \"the rise over the run.\"
\n" ); document.write( "The change in x = -6 -(-4) = -2
\n" ); document.write( "The change in y = 7 -(-3) = 10
\n" ); document.write( "The slope = 10/-2 = -5
\n" ); document.write( "So we now have:
\n" ); document.write( "y = -5x + b
\n" ); document.write( "But what is b?
\n" ); document.write( "Well, looking back at what was given, we know that when x = -4, y = -3.
\n" ); document.write( "Plugging in x = -4
\n" ); document.write( "y = -5(-4) + b
\n" ); document.write( "y = 20 + b
\n" ); document.write( "So, b = -23 to arrive at the point (-4,-3)
\n" ); document.write( "We also have the point (-6,7)
\n" ); document.write( "Plugging these into the formula we have:
\n" ); document.write( "7 = -5(-6) + b
\n" ); document.write( "7 = 30 + b
\n" ); document.write( "b = -23
\n" ); document.write( "That's the same answer as before.
\n" ); document.write( "So, the answer is: y = -5x -23
\n" ); document.write( "The graph can be used to check this.
\n" ); document.write( " $\"graph%28500%2C500%2C-25%2C25%2C-25%2C25%2C-5%2Ax-23%29\"$ \n" ); document.write( "

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