A piece of glass with an initial temperature of 99^\circ \text{C}99 ∘ C99, degrees, start text, C, end text is cooled at a rate of 3.5 ^\circ\text{C}3.5 ∘ C3, point, 5, degrees, start text, C, end text per minute. Concurrently, a piece of copper with an initial temperature of 0^\circ \text{C}0 ∘ C0, degrees, start text, C, end text is heated at 2.5 ^\circ\text{C}2.5 ∘ C2, point, 5, degrees, start text, C, end text per minute. Which of the following systems of equations can be used to solve for the temperature, TTT, in degrees Celsius, and the time, mmm, in minutes, when the glass and copper reach the same temperatures?