document.write( "Question 201391: write an equation in standard form for a line passing through the pair of points.\r
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document.write( "(-2,0) and (4,-5)\r
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document.write( "possible answers:
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document.write( "2x-9y=-37
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document.write( "-5x-6y=10
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document.write( "-2x+9y=-37
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document.write( "5x-6y=10 \n" );
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Algebra.Com's Answer #151618 by algebrapro18(249)![]() ![]() ![]() You can put this solution on YOUR website! write an equation in standard form for a line passing through the pair of points. (-2,0) and (4,-5). \r \n" ); document.write( "\n" ); document.write( "Well from the points given we know that: \r \n" ); document.write( "\n" ); document.write( "x1 = -2, y1= 0, x2 = 4, y2 = -5 \r \n" ); document.write( "\n" ); document.write( "First we need to find the slope of the line between those two points: \n" ); document.write( "That uses the formula: m = y2-y1/x2-x1 \r \n" ); document.write( "\n" ); document.write( "So from above we get that: m = (-5-0)/ (4--2) = -5/6. \r \n" ); document.write( "\n" ); document.write( "Now we can continue in 1 of two ways. Either we can plug in to the slope-intercept form and solve for b and then get into standard form, or we can use the point slope formula and get it in standard form. \r \n" ); document.write( "\n" ); document.write( "Option 1: slope-intercept form: \r \n" ); document.write( "\n" ); document.write( "we know that y = mx+b and we have a y, x, and m so we can solve for b. \r \n" ); document.write( "\n" ); document.write( "y = mx+b \n" ); document.write( "0 = -5/6(-2)+b \n" ); document.write( "0 = 5/3+b \n" ); document.write( "b = -5/3 \r \n" ); document.write( "\n" ); document.write( "or \r \n" ); document.write( "\n" ); document.write( "y = mx+b \n" ); document.write( "-5 = (-5/6)(4)+b \n" ); document.write( "-5 = -10/3 + b \n" ); document.write( "-5/3 = b \r \n" ); document.write( "\n" ); document.write( "so now we know that y = -5/6x-5/3. To get it into standard form we need to get the x and the y isolated on the same side. \r \n" ); document.write( "\n" ); document.write( "y = -5/6x-5/3 \n" ); document.write( "6y = -5x - 10 \n" ); document.write( "5x + 6y = -10 \n" ); document.write( "-(5x+6y) = 10 \n" ); document.write( "-5x-6y = 10 \r \n" ); document.write( "\n" ); document.write( "Option 2: Point-Slope form \n" ); document.write( "We know that y-y1=m(x-x1) so now we just plug in and simplify(not solve). \r \n" ); document.write( "\n" ); document.write( "y - 0 = -5/6(x--2) \n" ); document.write( "y = -5/6(x+2) \n" ); document.write( "y = -5/6x-5/3 \r \n" ); document.write( "\n" ); document.write( "and now we just need to get into standard form. \r \n" ); document.write( "\n" ); document.write( "y = -5/6x-5/3 \n" ); document.write( "6y = -5x - 10 \n" ); document.write( "5x + 6y = -10 \n" ); document.write( "-(5x+6y) = 10 \n" ); document.write( "-5x-6y = 10 \r \n" ); document.write( "\n" ); document.write( "Now I will leave it to you to check our answer, and you will see its right. \n" ); document.write( " |