The answer is 4 because you can put it this way 8-4!=4 or you can do it with fingers like☝☝☝☝☝☝☝☝-☝☝☝☝=☝☝☝☝
I think Its B just for sum point thought just ignore this
Roket leugue will help you solve that but for now its 9
Name an example of wedge. screw. inclined plane. lever. pulley. wheel and axle.
door stop. drill bit. truck loading ramp. nut cracker. crane. door knob.
Answer:
i think it's option b bcz it says it produces change in the shapes of these mountains.