Answer:
-2
Explanation:
8y+10-4+5y 
10+ -4 + 8y + -5y =0
10+ -4=0
6+8y + -5=0
8y + -5y= 3y
6+3y=0
6+ 3y =0
then add -6 at the end of the equation 
6+-6+3y=0+-6 
continue term 
6+-3+3y=0+-6
3y = 0 + -6
combine term 
0+3y=0+ -6
3y = 0 +-6
divide each side by 3 
and you get -2