The equation of a circle is given in the form

, where
(a, b) is the centre of the circle
r = radius
We have the centre of the circle (-27, 120)
We can work out the radius by modelling the radius as the hypotenuse of a triangle as shown in the diagram below


The equation of the circle is
![[x-(-27)]^2+[y-120]^2=15129](https://tex.z-dn.net/?f=%5Bx-%28-27%29%5D%5E2%2B%5By-120%5D%5E2%3D15129)
![[x+27]^2+[y-120]^2=15129](https://tex.z-dn.net/?f=%5Bx%2B27%5D%5E2%2B%5By-120%5D%5E2%3D15129)
Correct answer: option number 4
Answer:
7k√2 - 10k - 4√2
Step-by-step explanation:
Factor the polynomial.
Factor
: One of two or more expressions that are multiplied together to get a product.
Polynomial
: An algebraic expression consisting of one or more summed terms, each term consisting of a constant multiplier and one or more variables raised to integral powers.
We rewrite the equation:
y = y0 * e ^ (- 0.0002 * t)
In this equation:
I = represents the initial amount of the isotope
We have then:
89% of the isotope left:
0.89 * y0 = y0 * e ^ (- 0.0002 * t)
We clear the time:
e ^ (- 0.0002 * t) = 0.89
Ln (e ^ (- 0.0002 * t)) = Ln (0.89)
-0.0002 * t = Ln (0.89)
t = Ln (0.89) / (- 0.0002)
t = 582.6690813
round to the nearest year:
t = 583 years
Answer:
There will be 89% of the isotope left in about:
t = 583 years
B I’m pretty sure okay bye