Not so sure about the second one, but the first one is pretty simple:
The area of a circle = pi x radius^2
Since you need to find the area of the entire dvd, I'm assuming they mean if the hole in the center wasn't there, so add that to the diameter.
12+1.5 = 13.5
Half of the diameter is the radius, so half of 13.5 = 6.75
Now, multiply pi (3.14) by the radius, but have the radius squared. You'd write the equation like this:
3.14 x 6.75^2 (or on paper, the ^2 would be a small two diagonal from the 5)
Actual answer: 143.06625
You can round that to 143.
Answer: 100+10+1
You basically place zeroes instead of the actual digit to find the value of each number.
Example:
855
800+50+5
Answer:
34
Step-by-step explanation:
-5y=-45
y=-45/-5
=9
y=9
then
5y-11=5×9-11
=45-11
=34
Answer: 57.1
Step-by-step explanation: To be complementary the angles have to add up to make a sum of 90.
90 - 32.9 = 57.1
The angles are 32.9 and 57.1.
Answer:Albert spent more on video games and 1/2>0.4
But Rosa spent more on pizza 2/5>.25
Step-by-step explanation: Rosa spent most of her allowance while Albert spent the least amount so Rosa spent more