I don't understand how to solve this, please help!

x+1 , x<-1

x²-bx-4  , -1≤x≤4

1/2 x +a

substitute x=-1 , continuous everywhere

x+1=x²-bx-4 when x=-1

-1+1=-1²-b-4

then for :

x²-bx-4=1/2 x +a for x=4

4²-4b-4=1/2x+a

16-4(3)-4=4/2+a

16-12-4-2=a

the equations will be :

x+1

x²-3x-4

1/2x-2

I hope this help

3x + 18 = 147°

step-by-step explanation:

3x + 18 = 147°, because the value of the central angle is equal to the value of the arc formed by it.

i hope i you.