document.write( "Question 880823: Give the slope-intercept form of the equation of the line that is perpendicular to –7x + 3y = 14 and contains P(–1, –9).\r \n" );
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document.write( "First find the slope of the given equation \n" );
document.write( "-7x + 3y = 14 \n" );
document.write( "add 7x on both sides of the equation \n" );
document.write( "3y = 7x+14 \n" );
document.write( "Divide everything by 3 \n" );
document.write( "3y/3 =7x/3 + 14/3 \n" );
document.write( "y =7x/3 + 14/3 \n" );
document.write( "Remember y = mx + b where m =slope and (0,b) is the y intercept \n" );
document.write( "Therefore the slope of this equation is 7/3 \n" );
document.write( "In order to have an equation that is perpendicular the slope must be the opposite reciprocal therefore the slope of the perpendicular equation is -3/7\r \n" );
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document.write( "Now using the perpendicular slope and points given solve the equation y = mx +B \n" );
document.write( "for b by plugging in the x, y and slope.\r \n" );
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document.write( "y = mx + b \n" );
document.write( "-9 = (-3/7)(-1) + b \n" );
document.write( "-9 = 3/7 + b \n" );
document.write( "subtract 3/7 on both sides \n" );
document.write( "-9 -(3/7) = b \n" );
document.write( "b = 66/7 \n" );
document.write( "Now plugging in our perpendicular slope and b into the y = mx + b the equation of the perpendicular line is formed\r \n" );
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document.write( "y = (-3/7)x - 66/7 \n" );
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