解方程 log2(x+14)+log(x+2)=log(x+6)+3
问题描述:
解方程 log2(x+14)+log(x+2)=log(x+6)+3
答
∵log2(x+14)-log 1/2 (x+2)=3+log2(x+6),
∴log2[(x+14)(x+2)=log2[8(x+6)],
∴(x+14)(x+2)=8(x+6),
解得x=2,或x=-10,
检验,得x=2.