1.(3a+7)(3a-7)+2a(2/3a-1)其中a=-3 2.试证明代数式（2x+3）（3x+2）-6x（x+3）+5x+3的值与x的取值无关（2）若2a次方=3,2的b'次方=6,求证b=a+1

(3a+7)(3a-7)+2a(2/3a-1)其中a=-3
=[3*(-3)+7][3*(-3)-7]+2*3(2/3*3-1)
=[-9+7][-9-7]+6(2-1)
=(-16)*(-2)+6
=32+6
=38
（2x+3）（3x+2）-6x（x+3）+5x+3
=6x^2+13x+6-6x^2-18x+5x+3
=6x^2-6x^2+13x+5x-18x+3+6
=6+3
=9
经化简代数式的值与x的取值无关
2^a=3
2^b=6
6=3*2
2^b=2^a*2
2^b=2^(a+1)
所以b=a+1