Question

log5(x^2+2x-2)=0,2log5(x+2)-log5y+1/2=0求y

Answer 1

log5(x^2+2x-2)=0,即

x^2+2x-2=1

x=1或x=-3（舍去）

2log5(x+2)-log5y+1/2=0,即

log5[3^2√5/y]=0,即

9√5/y=1

y=9√5