How do you find #u=3/4v-w# given v=<4,-3,5>, w=<2,6,-1> and z=<3,0,4>?

1 Answer
Jun 6, 2017

#u = <<0, - frac(9)(4), - frac(1)(4)>>#

Explanation:

We have: #u = frac(3)(4) v - w#

First, let's substitute the vector expressions in place of #v# and #w#:

#Rightarrow u = frac(3)(4) (4 i - 3 j + 5 k) - (3 i + 0 j + 4 k)#

Expanding the parentheses:

#Rightarrow u = 3 i - frac(9)(4) j + frac(15)(4) k - 3 i - 0 j - 4 k#

Collecting like vector components:

#Rightarrow u = 0 i - frac(9)(4) j - frac(1)(4) k#

#therefore u = <<0, - frac(9)(4), - frac(1)(4)>>#

Therefore, the vector #u# is simplified to #<<0, - frac(9)(4), - frac(1)(4)>>#.