If we translate the vector n = (1, - 2) according to the vector a = (1, - 1) to get the vector m, then what is the modulus / M / = of the vector

If we translate the vector n = (1, - 2) according to the vector a = (1, - 1) to get the vector m, then what is the modulus / M / = of the vector

If the vector is equal to the original vector after translation, then | m | = | n | = √ 5