Problem 34

Question

In Exercises \(21-38,\) let $$\mathbf{u}=2 \mathbf{i}-5 \mathbf{j}, \mathbf{v}=-3 \mathbf{i}+7 \mathbf{j}, \text { and } \mathbf{w}=-\mathbf{i}-6 \mathbf{j}$$ Find each specified vector or scalar. $$4 w-3 v$$

Step-by-Step Solution

Verified
Answer
The answer is \(5\mathbf{i}-45\mathbf{j}\)
1Step 1 - Scalar Multiplication
Perform scalar multiplication for \(4 \mathbf{w}\) and \(3 \mathbf{v}\):\[4 \mathbf{w}=4(-\mathbf{i}-6 \mathbf{j})=-4 \mathbf{i}-24 \mathbf{j}\] and\[-3 \mathbf{v}=-3(-3 \mathbf{i}+7 \mathbf{j})=9 \mathbf{i}-21 \mathbf{j}\]
2Step 2 - Vector Addition
Add both vectors obtained in Step 1:\[-4 \mathbf{i}-24 \mathbf{j} + 9 \mathbf{i}-21 \mathbf{j} = (9-4)\mathbf{i} +(-21-24)\mathbf{j} = 5\mathbf{i}-45\mathbf{j}\]