Why l-3l + l9l represents the distance between the points (-3,-5) and (9, -5)

Graph red beads cost $1 an ounce and gold beads cost $3 an ounce. juanita wants to purchase a 12-ounce mixture of red and gold beads that she can sell for $2 an ounce. the solution of the system shows the number of beads needed for juanita to break even. x + y = 12, x + 3y = 24 how many ounces of red beads will juanita buy to break even? how many ounces of gold beads will she buy?

100 points, hi, i’m not sure what to do here, the data doesn’t seem to be quadratic .? can anyone me, in advance

Determine domain and range, largest open interval, and intervals which function is continuous.