For substitution this is what answer I got but I don’t know if that’s what your looking for
If the line is perpendicular to y=5/2X+4, then the line will the the negative reciprocal of the line. The slope of the new line will be -2/5x. Now plugging in the points in the formula should result in the new line being -2/5x-6
Every yard has 36 inches, so 7 yards is 252 inches
If

then we should have

Differentiating with respect to
gives


So
is indeed conservative, and
