Answer:
or 
Step-by-step explanation:
we have

step 1
Group terms that contain the same variable

step 2
Combine like terms

step 3
Eliminate parenthesis

step 4
Factor the number 

The answer will be 210 seconds. 60 X 3 = 180+ 30= 210
Step-by-step explanation:
Answer:
A I think
Step-by-step explanation:
because if you add them up.
475,536,821= (400,000,000×1) (70,000,000×1) (5,000,000×1) (500,000×1) (30,000×1) (6,000×1) (800×1) (20×1) (1×1)