(${√{a}} +{√{8a}})^2$ = 54 + b${√{2}}$
(${√{a}} + {√{8a}}$)(${√{a}} + {√{8a}}$)
a + 4a${√{2}} + 8a = 54 + b{√{2}}$
9a + 4a${√{2}}$ = 54 + b${√{2}}$
comparing both sides
9a = 54, so that a = 6
4a = b
b = 4 x 6 = 24.
