To get a perpendicular line to y=-2/5x+6 all you need to do is get the negative reciprocal of the slope then use (2,-3) and point slope formula to get your new equation.
y=-2/5x+6
m=-2/5 so new equation slope is m=5/2
y−b=m(x−a) or y-y1=m(x-x1)
point is (2,-3)
plug and chug
y-(-3)=5/2(x-2)
y=5/2x-8