Which mathematical property does (2+3)+4=2+(3+4) illustrate?

#1-20 state whether the angles are alternate interior, alternate exterior, vertical, or corresponding angles.

Tomas used 3 1/3 cups of flour and now has 1 2/3cups left. which equation can he use to find f, the number of cups of flour he had to begin with? f+3 1/3=1 2/3 f-3 1/3=1 2/3 3 1/3f=1 2/3 f/3 1/3=1 2/3

Y=x+2 4x+3y= -36 system of equation