Please help me:
In the figure, what is the value of x?
*45
*60
*75
*90

90

Step-by-step explanation:

The angle formed outside = 1/2(difference of intercepted arcs)

The large arc is 360-x and the inner arc is x

x = 1/2 (360 -x - x)

x = 1/2 (360 -2x)

Multiply each side by 2

2x = 360 -2x

Add 2x to each side

2x+2x = 360

4x= 360

Divide by 4

4x/4 = 360/4

x = 90

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