" the difference" means subtract
3(n - 5) <== ur expression
The two numbers with the sum of 9 and difference of 1 is 5 and 4. Explanation: Let the two numbers be x and y.
<span>The difference of the vectors; sample: the other diagonal would be the sum of one of the vectors and the opposite of the other vector, so it would be the difference.
</span>
Not completely sure on the symbols, but I think it is 5 x ( 22 - 9 x 2 ) - 2 ( 3 x 2 x 4 ) x 7 = 136. It doesn't really match the answers, so my advice is that you use a calculator for this one, or as the person/teacher who gave you the problem how to solve it.
