Arithmetic Series
Find the sum of the first 27 terms for the arithmetic series (S27):
20 + 18 + 16 + 14 +...+(-30) + (- 32) =
0 - 324
O- 162
O - 12
-5.16222 x 1033

step-by-step explanation:

i dont get

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

multiply each number by ten to get a simplified answer of 7/1.