What is three billion, two million, forty-two thousand, seven hundred sixty-five in expanded form

Which statement is true 1.the pythagorean theorem can be used to find the missing side of any triangle 2.the pythagorean theorem can be used to find the missing side of any polygon 3. the pythagorean theorem can be used to find the missing side of any right triangle 4.the pythagorean theorem can be used to find the missing side of any isosceles triangle

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

We just started the introduction into circles and i have no idea how to do this.