4. determine the center and radius of each circle.
a. 3x2^+3y^2=75
b. 2(x+1)^2+2(y+2)^2=10
c. 4(x−2)^2+4(y−9)^2−64=0

Step-by-step explanation:

Equation of circle with (h,k) as center and radius r is given by,

          (x-h)²+(y-k)² = r²

a) 3x²+3y²=75

   Dividing by 3

                    x²+y²=25

                    (x-0)²+(y-0)² = 5²  

          Center (0,0) and radius 5

b) 2(x+1)²+2(y+2)²=10

 Dividing by 2

        (x+1)²+(y+2)²=5

        (x-(-1))²+(y-(-2))²= 2.236²

          Center (-1,-2) and radius 2.236

c)  4(x−2)²+4(y−9)²−64=0  

           4(x−2)²+4(y−9)²= 64

 Dividing by 4

          (x−2)²+(y−9)²= 16

          (x−2)²+(y−9)²= 4²

          Center (2,9) and radius 4                                  

if you use photomath right away it will give you the answer not like this app that you have to wait for people.

62.5 paisa

step-by-step explanation:

4000*70 = 280000

280000-(2000*90) = 100000

4000-2400 = 1600

100000/1600 = 62.5

( give brainliest)