Dik : a = 7+√2 dan b = 7-√2 tentukan : a.3a + 4b b.2ab c.(a+b)² d.a²-b²

a. 3(7+√2) + 4(7-√2)
21 + 3√2 + 28 - 4√2
21 + 28 + 3√2 - 4√2
49-√2

b. 2(7+√2)(7-√2)
2(49-2)
2(47)
94

c. [(7+√2)+(7-√2)]²
(7+7+√2+√2)²
14²
169

d. (7+√2)²-(7-√2)²
49+14√2 +2-(49-14√2+2)
51+14√2-(51-14√2)
51+14√2-51+14√2
28√2