How to find range of g(x)=square4-x or g(x)=√4-x

g =-1 + 4x-1

Simplifying:  g(x) = 4 + -1x

Multiply g * x: g(x) = 4 + -1x

Solving: g(x) = 4 + -1x

Solving for variable g

Move all terms containing g to the left, all other terms to the right.