If y varies directly as y, and x=8 when y=4,find x when y=12​

Will give find an equivalent function to f(x)=5(2)^3x. the 5(2)^3x means 5(2) to the 3x power answer choices: a: f(x)=125^x(8)^x b: f(x)=10^2x c: f(x)=40^x d: f(x)=5(8)^x

Could someone with number 1 and 2

How do the definitions, properties, and postulates you've learned about line segments, parallel lines, and angles to define the shapes of polygons