Precalculus, Chapter 6, 6.3, Section 6.3, Problem 35

You need to evaluate the sum of two vectors,u+v, hence you need to perform the addition of the same versors, such that:
u = i + j
v = 2i - 3j
u + v = (1+2)i + (1-3)j
u + v = 3i - 2j
Hence, evaluating the sum u + v yields u + v = 3i - 2j
You need to evaluate the difference of two vectors,u-v , hence you need to perform the subtraction of the same versors, such that:
u = i + j
v = 2i - 3j
u - v = (1-2)i + (1+3)j
u - v = -i + 4j
Hence, evaluating the difference u - v yields u - v = -i + 4j.
You need to evaluate the difference of the vectors,2u-3v , hence you need to perform first the multiplication of each vector with the indicated scalar and then you need to perform the subtraction of the same versors, such that:
u = i + j => 2u = 2i + 2j
v = 2i - 3j=> 3v = 6i - 9j
2u - 3v =2i + 2j - 6i + 9j => 2u - 3v = -4i + 11j
Hence, evaluating the difference 2u - 3v yields 2u - 3v = -4i + 11j.