Answer:
2A) The centre is (-3,2) and the radius is 5.
Step-by-step explanation:
2A)
Okay so if you have the equation of a circle in standard from (ie it looks something like this: (x-h)² + (y-k)² = r² ), it's pretty easy to find the centre and radius because in this form, r is the radius and (h,k) is the centre of the circle.
Note that (x-h)² + (y-k)² = x²+(-2h)x+h² + y²+(-2k)y+k²
In our case [x²+y²+6x-4y-12=0], we can see that -2h=6 (because 6 is the coefficient of x) and -2k=-4 (because -4 is the coefficient of y).
-2h=6, h=-3
-2k=-4, k=2
Let's sub these in:
x²+(-2h)x+h² + y²+(-2k)y+k² = r²
x²+6x+(-3)² + y²-4y+(2)² = r²
x²+6x+9 + y²-4y+4 = r²
x²+y²+6x-4y+(13-r²)=0
x²+y²+6x-4y+(13-r²)=x²+y²+6x-4y-12=0
13-r²=-12
r²=25
r=5
So our equation in standard form is (x+3)²+(y-2)²=25, which means the centre is (-3,2) and the radius is 5.
Answer:
47.13 for 17 melons
Step-by-step explanation:
We can use a ratio to solve
24.95 x dollars
---------------- = ----------------
9 melons 17 melons
Using cross products
24.95 * 17 = 9x
Divide by 9
24.95 * 17/9 = x
47.127777777 = x
Rounding to the nearest cent
47.13 for 17 melons
Answer:
15x20
Step-by-step explanation:
If you look closely in the question, it says one inch is 10 feet in the actual room. So what you would do is take the measurements and multiple by 10. All sides of the room are 3 inches but what the trick is, it asks you for the dimensions of the kitchen. So you would multiple 2x10 and 1.5 x 10 :)!