Hi,
line perpendicular to 5x + 6y = 7
5x + 6y = 7
y = (-5/6)x + (7/6) slope of this line is (-5/6)
Note: slope of a lineprependicular to this will be (6/5) its negative reciprocal
Our perpendicular line
y = (6/5)x + b
Using ordered pair (3,-4) to solve for b
-4 = (6/5)*3 + b
-4 - (18/5) = b
(-38/5) = b
y = (6/5)x - (38/5) or in standard form 6x - 5y = 38