PLEASE HELP I'll give brainlest

The radius is half of diameter. so a radius of 6 would be a diameter of 12. to find the circumference it would be 2 times 3.14 times radius. and to find the area you do 3.14 times the radius times the radius again.
the first one would be: circumference= 37.68 diameter= 12 area= 113.04. hope the helps!

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.

The additive identity is 0 because when you add 0 to a number, you get the identical number as an answer.a + 0 = a