Question 710635
-s + 4 = 7s -3
 add s on both sides
 -s +4+s  = 7s -3 +s
           4= 8s -3
  add 3 on both sides
4+3  = 8s -3+3
 7 =8s
 divide with 8 on both sides  
 7/8  = 8s/8
 7/8  = s