Answer:
-4/5
Step-by-step explanation:
write the given equation in y=mx+b form, where m is the slope
10x-8y=-80
-8y= -10x-80 divide both sides by -8
y=(10/8)x+10
y=(5/4)x+10
m= 5/4 is the slope of the given function
the slope of an equation that is perpendicular is the negative reciprocal of the given one so is
m= -4/5
