What is the answer??????????????

Question

h- 34mm = 66mm, h=variable

Answer 1

h-34 = 66

add 34 to each side

h = 66 +34 = 100

Answer 2

h - 34 = 66

add 34 to each side

h - 34+(34) = 66+(34)

h = 66 +34 

h = 100.