2*5*3, you still get the same answer as (3*2)*5
I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
53,445,912. This answer is correct, as I did it by calculator. Good luck!
Answer:
x+3
Step-by-step explanation:
Answer:
4.589×10to the power of -11
Step-by-step explanation: