sqrt 98 + 3*sqrt 50 - sqrt 242

sqrt(49*2) + 3*sqrt(25*2) - sqrt(121*2)

sqrt(49)*sqrt(2) + 3*sqrt(25)*sqrt(2) - sqrt(121)*sqrt(2)

7*sqrt(2) + 3*5*sqrt(2) - 11*sqrt(2)

7*sqrt(2) + 15*sqrt(2) - 11*sqrt(2) ... since all terms have sqrt(2), they can be added (they are "like terms")

= 11*sqrt(2)