Question 442577
(7,-7)

{{{7x+2y=5}}}

{{{2y=-7x+5}}}

{{{y=-(7/2)x+5/5}}}

{{{y=-(3.5)x+2.5}}}


*[invoke equation_parallel_or_perpendicular "perpendicular", -3.5, 2.5, 7, -7]


so, the line {{{y=0.28x - 0.86}}} is  perpendicular to {{{y=-(3.5)x+2.5}}} and containing the given point (7,-7)