Question

Find a ⋅ b. a = 8i + 6j, b = 4i + 5j

Answer 1

32i+30j should be correct(hopfully)

Answer 2

You could rewrite this as double brackets, as you are multiplying together two sets of two terms. It would then look like:
(8i + 6j)(4i + 5j)
and you can expand by multiplying together all of the terms

8i × 4i = 32i²
8i × 5j = 40ij
6j × 4i = 24ij
6j × 5j = 30j²

To get your final answer, you then just need to add together all of the like terms, and get 32i² + 30j² + 64ij

I hope this helps!