First question.
We must subtitute w=-13 into the given equation:

then, we have

so, the answer is false.
Second question.
We must substitute c=-3 into the given equation:

which gives

so, the answer is true.
Third question.
We must substitute z=12 into the given equation:

which gives

so, the answer is true.
Fourth question.
We must substitute y=-5 into the given equation:

which gives

so, the answer is true.