clear perenthesis in distributive property-(-p-5q-10r)
Distributive properties
multiplication over addition/subtraction:
a(b±c) = ab ± ac
negation over addition/subtraction:
-(b+c) = -b - c
-(b-c) = -b + c
So applying the distributive properties of negation over addition/subtraction:
-(-p-5q-10r)
= p+5q+10r