Answer:
The law is the Inverse law of Addition/Multiplication
Step-by-step explanation:
Easy! 1 hour - 1 hour and 30 minutes = 30 minutes(together)
See attachment file below.
Hope it helped!!
<em>Your answer would be 5, just the number in general.</em>
<em>>[I'ma be honest here and say I had a fraction earlier :P</em>