Complete the square and then find the center and radius from the circle equation
x^2+y^2-4x+8y-5=0

  center: (2, -4); radius: 5

Step-by-step explanation:

Group x-terms and y-terms. Add the squares of half the coefficient of the linear term in each group. It can be convenient to subtract the constant, too.

  (x^2 -4x) +(y^2 +8y) = 5

  (x^2 -4x +4) +(y^2 +8x +16) = 5 + 4 + 16

  (x -2)^2 +(y +4)^2 = 5^2

Comparing this to the form of a circle centered at (h, k) with radius r, we can find the center and radius.

  (x -h)^2 +(y -k)^2 = r^2

  (h, k) = (2, -4) . . . . . the circle center

  r = 5 . . . . . . . . . . . . the radius

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950