Tara is using matrix multiplication to find image points of a translation. she is translating the image 2 units left and 4 units up. which should be her first matrix?

Assuming that this is just on a 2-D coordinate plane, we must convert the expressions on to a 3-D plane since translation cannot be done on a 2-D plane. This is done by adding a dummy coordinate that does not change. Let us use "1" for this case.

Matrix:
| 0 0 -2 |(x) = (x - 2)
| 0 0 4  |(y) = (y + 4)
| 0 0 1  |(1) = 1

Definitely