120
70+50=120
180-120=60
180-60=120
The answer is B) multiply 3 by 3. With that 2 on top, that doesn't mean 3 times 2, that means multiply 3 by itself, however many times the number says, if that makes sense. So if there's a 2 above the 3, then that would be 3*3. If it was a 5 instead of a two, that would mean 3*3*3*3*3. Not 3*5.
4. 8
/ \ / \
2 x 2. 4 x 2
/ \
2 x 2
4: 2x2
8: 2x2x2
The GCF is 4