document.write( "Question 525262: Write the slope-intercept equation for the line that passes through (-7, 6) and is perpendicular to -7x + 9y = -2 Please show all of your work.
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #348056 by oberobic(2304) $\"\"$ $\"About$

You can put this solution on YOUR website!
The line perpendicular to -7x +9y = -2 has the inverse reciprocal slope.
\n" ); document.write( "First get the line into slope-intercept form.
\n" ); document.write( "-7x +9y = -2
\n" ); document.write( "9y = 7x -2
\n" ); document.write( "y = (7/9)x - 2/9
\n" ); document.write( ".
\n" ); document.write( "m = slope = 7/9
\n" ); document.write( ".
\n" ); document.write( "So, the perpendicular line would have a slope of -9/7.
\n" ); document.write( ".
\n" ); document.write( "y = -(9/7)*x + b
\n" ); document.write( ".
\n" ); document.write( "Use the point (-7,6) to find 'b'.
\n" ); document.write( ".
\n" ); document.write( "6 = -(9/7)*(-7) + b
\n" ); document.write( "6 = 9 + b
\n" ); document.write( "b = -3
\n" ); document.write( ".
\n" ); document.write( "y = -(9/7)x -3
\n" ); document.write( ".
\n" ); document.write( "In the following graph:
\n" ); document.write( "the red line is y = (7/9)x - 2/9
\n" ); document.write( "the green line is y = -(9/7)x -3
\n" ); document.write( ".
\n" ); document.write( " $\"+graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C7%2F9%2Ax-2%2F9%2C-9%2F7%2Ax-3%29+\"$
\n" ); document.write( " \n" ); document.write( "

\n" );