Help me and show your work.

x = 129

Step-by-step explanation:

Mathematically, the sum of interior angles of a polygon can be calculated using the formula;

(n-2)180

from the question given , n = 7 since the polygon has 7 sides

thus, we have it that

(7-2)180 = 5 * 180 = 900

Mathematically, by adding all the given interior angles, we can get the value of the total

We have this as;

900 = x + 131 + 119 + 125 + 133 + 125+ 138

900 = x + 771

x = 900-771

x = 129

g

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