Solve this question
a=7+3

Step-by-step explanation:

The answer is 10 because 7 + 3 equals 10!

This can be proven by adding 7 + 3 or by subtracting in a certain way.

7 + 3 = ?

7 + 1 = 8

7 + 2 = 9

7 + 3 = 10

You can show more work by subtracting your answer or 10 in this case, which means that you subtract 7 by 10 or 3 by 10, either way is ok.

If you subtract 7 by 10, ( 10 - 7 ) then you get 3

If you subtract 3 by 10, ( 10 - 3 ) then you get 7

If the number you subtracted matches the number that you didn't subtract, then your answer is correct.

Hope this helps! <3

1,407.5 hours

step-by-step explanation:

we first convert all the time to hours and then sum them up.

there are 24 hours in 1 day, in 58 days, there are 24 x 58 = 1,392 hours.

there are 60 minutes in 1 hour, thus, 30 minutes will be equivalent to 30 / 60 = 0.5 hours.

therefore, the number of hours it will take mercury to complete a full rotation is 1,392 + 15 + 0.5 = 1,407.5 hours

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64