Question 199346
-6r +s -rs
.
r(-6-s) +s
.
5(-6-7) +7
.
5(-13) +7
.
-65 +7
.
-58
.
check using  direct  subst  into  initial  eqn
.
-6(5)+(7) -(5)(7) = -30 +7 -35 = -65 +7 =-58,,,,ok