Question

Given v = 7i − 9j and w = −6i + 8j, find 7v − 2w.

Answer 1

Explanation

Given

$\begin{gathered} v=7i−9j \\ w=−6i+8j \end{gathered}$

Therefore;

$\begin{gathered} 7v−2w=7(7i−9j)-2(−6i+8j) \\ open\text{ parenthesis} \\ =49i-63j+12i-16j \\ collect\text{ like terms} \\ =49i+12i-63j-16j \\ simplify \\ =61i-79j \end{gathered}$

Answer: 61i-79j