Find the mean of the squares of the first 10 counting numbers.

38.5

Step-by-step explanation:

Find the mean of the squares of the first 10 counting numbers ... Mean = 1 + 4 + 9 + 16 + 25 + 36 + 49 + 64 + 81 + 100 / 10 = 385 / 10 = 38.5

where r the answers

step-by-step explanation:

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