A) -6a = 36
Divide both sides by -6 so that (a) is isolated.
a = -6
Check by plugging in -6 for a.
-6a=36
-6(-6)=36
36=36
So, a=-6
B) -9d=-72
Divide both sides by -9.
d = -72/-9
d = 8
Check work by plugging in 8 for d.
-9d=-72
-9(8)=-72
-72=-72
So, d=8
~Hope I helped!~
This is an arith. sequence, and the common difference is -9.
a(n+1) = a(n)-9, with a(1)=8. Thus, if we look at the first term, we see 8; subracting 9 from 8 produces the second term (-1).
