What does this symbol mean? "∩" and this symbol "∈" and how do you use them?

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

Rai compares two cable plans from different companies. which equation gives the correct value of mm, the number of months for which plans a and b cost the same?

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1