Hi!
The equation of a circle is (x – h)² + (y – k)² = r², with (h, k) being the center, r being the radius, and x + y being left as just x and y.
If the smallest circle has a radius of 3 units, then the next one is 7 units (4 units greater), and then the second largest 11 units, and then the largest 15. That means, for r in our equation, we're going to put in 15.
So we get:
(x – h)² + (y – k)² = 15², or
(x – h)² + (y – k)² = 225
The center of our circle is at (-4, 3). That means h = -4 and k = 3 in our equation. So let's substitute that in.
(x – (-4))² + (y – 3)² = 225
(x + 4)² + (y - 3)² = 225 is our final equation.
Hope this helped!
Answer:
one card takes 1/12 of an hour or 60/12=5 minutes.
she has 3/4 of an hour or 60×3/4=45 minutes
number of cards she can make =45/5=9
Answer: You can buy 12 magazines
Step-by-step explanation: Can I have brainlest?
Answer:
x=6
Step-by-step explanation:
81^x = 27 ^(x+2)
81 = 3^4 and 27 =3^3 so replace 81 and 27 in the equation
3^4^x = 3^3^(x+2)
When we have a power to a power we can multiply the exponents
a ^b^c = a^(b*c)
3^(4x) = 3^(3*(x+2))
Since the bases are the same, the exponents have to be the same
a^b = a^c means b=c
4x = 3(x+2)
Now we can solve for x
Distribute
4x = 3x+6
Subtract 3x from each side
4x-3x = 3x-3x+6
x = 6
