Si el doble de un número más 30 es igual 84¿que número es?​

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?

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

Answer asap! urgent! will give brainliest!