Pls awnser I will give brainliest

9514 1404 393

  C.  22/7

Step-by-step explanation:

You may be aware that 22/7 is a value used to approximate π almost as often as is 3.14.

__

In case you actually want to carry out the calculations, you have ...

  C = πd

  π = C/d

  π ≈ (60 3/50)/(19 11/100) = (3003/50)/(1911/100) = 6006/1911 = 22/7

  π ≈ 77/(24 1/2) = 77/(49/2) = 22/7

  π ≈ (86 9/10)/(27 13/20) = (869/10)/(553/20) = 1738/553 = 22/7

  π ≈ 99/(31 1/2) = 99/(63/2) = 22/7

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15