15.
2(3+1)= 6x+3
Distribute
6x+2=6x+3
Subtract 2 from both sides
6x= 6x+1
Subtract 6x from both sides
0=1
What happens is that we end up with a statement that is not true. What this means is that there is no solution.
16.
She is incorrect. When you end up with a true statement (in this case, 0=0), that means that there are infinitely many possible solutions.
