4^x+6^x-9^x=0
热心网友
4^x+6^x-9^x=0---(4/9)^x+(6/9)^x-1=0---[(2/3)^x]^2+(2/3)^x-1=0---[(2/3)^x+(1+√5)/2]*[(2/3)^x-(√5-1)/2]=0(2/3)^x0---(2/3)^x-(√5-1)/2=0---(2/3)^x=(√5-1)/2---x=lg[(√5-1)/2]/lg(2/3)
热心网友
2^2x+2^x*3^x-3^2x=0
热心网友
4^x+6^x-2×9^x=0?(2^x)^2+2^x×3^x-2×(3^x)^2=0( 2^x - 3^x ) ( 2^x + 2×3^x ) = 0∵2^x + 2×3^x 0∴2^x - 3^x =0即2^x = 3^x 两边取对数，xlg2=xlg3∴x=0。对不起,我弄错了.看二楼的吧.