√6−√5√6+√5 = ________.
4√30
11
11−2√30
11−√30
√6−√5√6+√5×√6−√5√6−√5
=(√6−√5)2(√6)2−(√5)2
=(√6)2−2(√6)(√5)+(√5)26−5
= 6−2√30+51
= 11−2√30
Let N = 45+45+45+4535+35+35⋅65+65+65+65+65+6525+25 then the value of log2N =