Question

已知9+根号11和9-根号11的小树部分分别为a,b （1）求a,b的值； （2）计算ab-3a+4b-7的值.

Answer 1

(1) gen 11 约3.***,则：

a=9+gen11-12=gen11-3

b=9-gen11-5=4-gen11

(2)ab-3a+4b-7

=a*(b-3)+4*b-12+5

=a*(b-3)+4*(b-3)+5

=(a+4)*(b-3)+5

=(gen11-3+4)*(4-gen11-3)+5

=(gen11+1)*(1-gen11)+5

=1-(ge11)^2+5

=1-11+5

=-5

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