What are the problems by finding the greatest common factor?

Abag has more green balls than blue balls, and there is at least one blue ball. let bb represent the number of blue balls and let gg represent the number of green balls. let's compare the expressions 2b2b and b + gb+g. which statement is correct? choose 1

Ef is a median of trapezoid abcd. the length of ab is 12, and the length of cd is 18. the length of bf is 4. what is the length of fc?

To start to solve the system of equations below, which number would you multiply in the equation -2x-5y=-1? the two equations are -2x-5y=-1 and 4x+2y=8