Which system of equations has exactly one solution? 2 x minus 4 y = 8. x + y = 7.
3 x + y = negative 1. 6 x + 2 y = negative 2.
3 x + 3 y = 3. Negative 6 x minus 6 y = 3.
3 x minus 2 y = 4. Negative 3 x + 2 y = 4.

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )