I need hellppp on this one

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?

Adolphin jumps from 5 feet below the surface of the sea. jane wrote -5 to represent the death from which the dolphin jumped. what does zero represent in this situation?

Ellinor made tables of values to solve a system of equations. first she foundthat the x-value of the solution was between 0 and 1, and then she found thatit was between 0.5 and 1. next, she made this table.which ordered pair is the best approximation of the solution?