Slide 8 left and 5 down

Four individuals pool money together to start a new business and agree to split the profits equally. n invests $6,000, x invests $2,000, y invests $8,000 and z invests $4,000. if the profits for the first month were $100,000, y receives than if the profits were divided in proportion to how much they invested.

Which graph represents the equation y =4x

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?