Is y= 2x cubed +6 linear or non-linear

Find the solution of system of equation y= x-4 y=4x+2

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?