Solve for B a = bc+b

I thought I knew how to do this but I guess I didn't.. help please

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?

Factor the expression using gcf 9b+45

When a valve is open 281 gallons of water go through it in one hour the number of gallons that would go through in 94 hours is