first replace the letters with the numbers it gave so you have 3(2)(7)^2-(2)^2
multiply the 3 and 2 together to make 6(7)^2-(2)^2
do seven to the second power (7x7) so you get 6(49)-(2)^2
-(2)^2 is the same as -1(2)^2, so that can just become -2^2. so you now have 6(49)-2^2
multiply 6x49 so you have 294-2^2
do two to the second power (2x2) so you get 294-4
294-4=290
