2 & lt√7 & lt； The integer part of 3,5-√ 7 is 2, and the decimal part is 3-√7. That is, m = 2 and n = 3-√ 7.

Shit, amn+bn? = 1，2a(3-√7)+b( 16-6√7)= 1，6a+ 16b-(2√7a+6√7b)= 1，

2√7a+6√7b=0，a+3b=0 .6a=- 18b，-2b= 1，b=-0.5，a= 1.5。

2a+b=2.5 .