Answer:
centre = (2, - 1), radius = 6
Step-by-step explanation:
Rearrange the equation by placing the x and y terms together and adding 31 to both sides
Given
x² + y² - 4x + 2y - 31 = 0, then
x² - 4x + y² + 2y = 31
Use the method of completing the square
add ( half the coefficient of the x/y term )² to both sides
x² + 2(- 2)x + 4 + y² + 2(1)y + 1 = 31 + 4 + 1
(x - 2)² + (y + 1)² = 36
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r the radius
compare to (x - 2)² + (y + 1)² = 36, then
centre = (2, - 1) and r =
= 6
Answer:
6²
Step-by-step explanation:
Using the rule of exponents
⇔
, then

= 
= 6²
Answer:
- w + b = 13
- 6.5w + 2b = 57.5
Step-by-step explanation:
Let w represent the number of gifts wrapped. Let b represent the number of bags prepared.
w + b = 13 . . . . gift bags and gifts wrapped
6.5w +2b = 57.5 . . . . total time spent preparing gifts
_____
Lincoln wrapped 7 gifts and bagged 6.
Answer: 624
Step-by-step explanation:
12 times 8 is 96 and 96 divided by 2 is 48 and 48 times 13 is 624
4/6=66.67%
5/8=62.5%
Therfore 4/6 is bigger than 5/8