(√6 + 1)^2 = (√6 + 1)(√6 + 1)
= (√6 √6) + (√6 1) + (1 √6) + (1 1)
= 6 + 2√6 + 1
= 7 + 2√6

Итак, (√6 + 1)^2 = 7 + 2√6.