There are 60 seconds in a minute.
There are 60 minutes in an hour.
This means that there'd be 600 minutes in 10 hours.
And if there are 60 seconds in a minute, there are 600 x 60 seconds in 600 minutes.
600 x 60 = 600 x 10 x 6 = 6000 x 6 = 36000
So we know that there are 36000 seconds in 10 hours.
The subtraction sign in front of the second set of parenthesis changes the signs on the terms inside those parenthesis. So this could be rewritten as

. None of the exponents on the x are the same, so we will just express it in terms of descending powers of x.

. This is also the same as

if you don't like to start with a negative. Either one is correct.
Sorry but I can’t see the picture
Answer:
12
Step-by-step explanation:
Use pythag to solve.
x^2+5^2=13^2
x=12
945 rounded to the nearest ten is 950