the answer is B. 16 because you multiply 4 with 2s and -1 so the new equation will be 8s-4=7s+12 and you have to subtract the variable 7s to 8s the equation will be 1s-4=12 and add 4 to 12 and it gives you 16 and just divide 16 and one and you answer should be 16. :)
