How do you solve this problem?

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain

The length and width of a rectangle are consecutive even integers the area of the rectangle is 120 squares units what are the length and width of the rectangle