Question

13=5-8m show work thank u

Answer 1

13=5-8m
8=-8m
8/-8=-1
-1=m 

Answer 2

$13=5-8m \\ \\ 13-5=5-8m-5 \\ \\ 8=-8m \\ \\ \frac{8}{-8} = \frac{-8m}{-8} \\ \\ -1=m$