What are simple machines and what is a fulcrum. first class lever second and third lever

A Simple Machine is the Basic Device/Part of any Major Physically Operated System, and is a Machine based on Force Input and Output. Simple Machines are 5 machines that are lone, These 5 Simple Machines are an Inclined Plane, A Screw, Wheel and Axle, Pulley, and a Wedge.
And a Fulcrum is the point the Lever rests on and/or is Basically the Base of the Lever, like a Seesaw for Example.

C.about 10% i think

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].