Ineed finding the common difference for 3 !

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?

Ten times the square of a non-zero number is eqaul to ninety times the number

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?