Question

PLS HELP ME ANSWER THIS ASAP , I WILL GIVE EXTRA POINTS AND BRAINIEST.

Answer 1

a-5.1=1.7
+5.1 on both sides
a=6.8

-31=z+(-17)
+17 on both sides.
-14 = z

Answer 2

a - 5.1 = 1.7
a = 1.7 + 5.1
a = 6.8

-31 = z + (-17)
-31 = z - 17
- 31 + 17 = z
z = -14