解方程log以(x+2)为底(4x+5)-log以(4x+5)为底(x²+4x+4)-1=0
问题描述:
解方程log以(x+2)为底(4x+5)-log以(4x+5)为底(x²+4x+4)-1=0
答
log以(4x+5)为底(x²+4x+4)=log以(4x+5)为底(x+2)²=2log以(4x+5)为底(x+2)令log以(x+2)为底(4x+5)=t则t-2/t-1=0∴ t²-t-2=0∴ (t-2)(t+1)=0即 t=2或t=-1(1)log以(x+2)为底(4x+5)=2即 (x+2)²=4x...