Starting equation is 2log7(−2r)=0
First we can divide both sides by 2
log7(−2r)=0
Now we have to write the right side (0) as a logarythm.
Since 70=1, we can write 0 as log71, so the equation becomes:
log7(−2r)=log71
We can skip log signs because both sides are logarythms and the base is the same:
−2r=1
Now if we divide the equation by (-2) we get the answer: