Answer:
see explanation
Step-by-step explanation:
(1)
p + q
= 2i - j + i + j ← collect like terms
= 3i
(2)
p - q
= 2i - j - (i + j) ← distribute parenthesis by - 1
= 2i - j - i - j ← collect like terms
= i - 2j
(3)
2p - 3q
= 2(2i - j) - 3(i + j) ← distribute parenthesis
= 4i - 2j - 3i - 3j ← collect like terms
= i - 5j
