2z + 9.75 -7z = -5.15
2z - 7z + 9.75 = -5.15
-5z + 9.75 = -5.15
-5z + 9.75 - 9.75 = -5.15 - 9.75
-5z = -14.9
-5z/-5 = -14.9/-5
z = 2.98
I hope this helps
