Answer:
I just did for your previous posting.
300ft cause A=lw and it said its a square so all sides are the sam
so
300 times 300 = 900
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!:)
1 m=1000cm, so 21m=2100cm
1min=60sec
so 21 m/min=2100сm/60sec=35cm/sec
Answer:
2^4 or 16
Step-by-step explanation:
We know that a^b / a^c = a^(b-c)
2^9 / 2^5
2^(9-5)
2^4 or 16