Carla adds together the multiples of 3, in order and tell her friends to guess which number was the last one she added if her total is 84

28

Step-by-step explanation:

I know that 20 times 3 equals 60 and that 24 plus 60 equals 84 so we need to find out what times 3 equals 24 I know that 8 times 3 equals 24 so we add 20 and 8 to get our answer 28

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.