Answer:
Step-by-step explanation:
A=2i+3j+4k
B=i-2j+3k
Sum of the vectors:
A + B = 2i+3j+4k + i-2j+3k = 3i + j + 7k
Direction of the sum of the vectors:

40/1 is the same 80/2 120/3 160/4
The value of the given expression is 
Solution:
Given expression is
.
Let us first convert mixed fraction into improper fraction.

Substitute this in the given expression.


To simplify the above expression, 21 and 60 are cancelled by 3.

Do cross multiplication to make the denominator same.



The value of the given expression is 
Answer: 720
Step-by-step explanation: if what you want are all possible three digit numbers with no repetition of the digits then you have 10 choices for the first digit, you have 9 choices for the 2nd digit, and you have 8 choices for the 3rd digit giving you 10x9x8 = 720 in all.