8x-9y=1 (3,-4) slope intercept form

1. what are the missing reasons in the proof 2. it's in the second picture and 3

Five dinosaurs go for a walk and come across some lovely chicken wings. their names are rexy, bronto, steggy, paly, and terry. there are exactly 5 dozen wings(equal enough for each dino to have a dozen right? ); however, terry is on a diet and he only eats 6 wings. if paly eats 2 more than terry, steggy eats 4 more than paly, and bronto and rexy eat the same amount because they are really hungry from not eating all day, how many chicken wings did each dino eat?

Eileen purchased 3.4 pounds of apples at the total cost of $19.72. if she purchases 6.2 pounds of apples at this store, how much would it cost?