Answer:
centre = (2, - 3 ) and radius = 5
Step-by-step explanation:
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 is the radius
given
x² + y² - 4x + 6y - 12 = 0 ( add 12 to both sides )
x² + y² - 4x + 6y = 12 ( collect x/ y terms )
x² + 4x + y² + 6y = 12
using the method of completing the square
add ( half the coefficient of the x/ y terms )² to both sides
x² + 2(-2)x + 4 + y² + 2(3)y + 9 = 12 + 4 + 9
(x - 2)² + (y + 3)² = 25 ← in standard form
with (h, k ) = ( 2, - 3 ) and r = 
= 5
Answer:
The length is 72
Step-by-step explanation:
length x width = area
9 x length = 648
length = 72
Answer:
D
Step-by-step explanation:
So you start with $2.65 and a variable y. What we will do is work without the dollar and keep it for the end as it quite disturbs and work our way while keeping the y. So first we have 2.65. Now it rose by y so. The price = 2.65 + y. Then it dropped by 0.15. So 2.65 + y - 0.15. Here you see we have like terms so we reduce and get 2.50 + y. Now it rose by 0.05. So 2.50 + y + 0.05. Again, like terms, reduce. 2.55 + y. There you go with the answer.
Answer:
what do you need help with? can you explain please
Answer:
28 short race volunteers
76 long race volunteers
Step-by-step explanation:
Let :
Short races = a
Long races = b
LAST YEAR:
7a + 8b = 804 - - - - (1)
THIS YEAR:
11a + 5b = 688 - - - (2)
Multiply (1) by 5 and (2) by 8
35a + 40b = 4020
88a + 40b = 5504
Subtract
-53a = - 1484
a = 1484 / 53
a = 28
Put a = 28 in equation (1)
7(28) + 8b = 804
196 + 8b = 804
8b = 804 - 196
8b = 608
b = 76
28 short race volunteers
76 long race volunteers
