Find a ⋅ b a = 7i – 4j, b = 4i + 3j
Answer:
28i^2 + 5ij – 12j^2
Step-by-step explanation:
(7i-4j)(4i+3j)
7i times 4i is 28i^2
7i times 3j is 21ij
-4j times 4i is -16ij
-4j times 3j is -12j^2
In equation it looks like this:
28i^2+21ij-16ij-12j^2
Simplify 21ij and -16ij
21ij-16ij is 5ij
So the answer is:
28i^2 + 5ij – 12j^2