Question

Find a ⋅ b
a = 7i - 4j, b = 4i + 3j

Answer 1

The answer is 16

Explanation:

Answer 2

28i^2 + 5ij - 12j^2

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

Hope this helps!