a = 3^2 - (√5)^2 + (2√3)^2 - 2*2√3*2 +2^2 + (√6)^2 + 2*√6*2
a = 9 - 5 +12 - 8√3 + 4 + 6 + 4√6
a = 26 - 8√3 + 4√6
a = 4(6 - 2√3 + √6)
b = 28 + 3*1 + 10*(-1) + 5^12 : 5^10
b = 28 + 3 - 10 + 5^2
b = 21 + 25
b = 46
1/(4-√7) + 1/(4+√7) =
= (La prima fractie rationalizezi cu 4+√7 ) => (4+√7)/ 9 + ( La a doua fractie rationalizezi cu 4-√7) => (4-√7)/9 => (4+√7)/9 + (4-√7)/9 = 8/9