The correct option is d. 15
Step-by-step explanation:
Consider the provided information.
We need to find the a ⋅ b
The given vector is:
a = 9i - 6j, b = 5i + 5j
![\vec{a} = 9i - 6j \cdot \vec{b}= 5i + 5j](/tpl/images/0351/4697/6424b.png)
Use the vector multiplication as shown:
is defined as:
![a\cdot b =a_1b_1+a_2b_2...a_nb_n](/tpl/images/0351/4697/45490.png)
Now by using the above formula:
![\vec{a}=9i-6j\cdot \vec{b}= 5i + 5j=45-30=15](/tpl/images/0351/4697/96787.png)
Hence, the correct option is d. 15