What is the value of x?

The value of x is (answer in degrees)

57 degrees

Step-by-step explanation:

Since 2 of the sides are equal, this means that the triangle is an isosceles triangle, which means that the 3rd angle(the angle not labeled) will also equal to x. Therefore, we can set up an equation and solve for x:

x+x+66=180

2x+66=180

2x=114

x=57

21

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