Answer:
55
Step-by-step explanation:
IHG = 123
IHS = x + 65
SHG = x + 78
IHG = IHS + SHG
123 = x + 65 + x + 78
123 = 2x + 143
123 - 143 = 2x
-20 = 2x
-10 = x
IHS = - 10 + 65
IHS = 55
