For this answer I believe it would be best if you did it on paper
Answer:
2u + v - 4w = <40 , -4>
6u - 8v = <-78 , 58>
4v - 7w = <101 , -36>
11u + 3w = <-88 , 89>
Step-by-step explanation:
* Lets find the value of each operation to find its resultant vector
# 2u + v - 4w
∵ u = <-5 , 7>
∴ 2u = <-10 , 14>
∵ v = <6 , -2>
∵ w = <-11 , 4>
∴ 4w = <-44 , 16>
∴ 2u + v - 4w = <-10 + 6 - -44 , 14 + -2 - 16>
∴ 2u + v - 4w = <40 , -4>
# 6u - 8v
∵ u = <-5 , 7>
∴ 6u = <-30 , 42>
∵ v = <6 , -2>
∵8v = <48 , -16>
∴ 6u - 8v = <-30 - 48 , 42 - -16>
∴ 6u - 8v = <-78 , 58>
# 4v - 7w
∵ v = <6 , -2>
∴ 4v = <24 , -8>
∵ w = <-11 , 4>
∴ 7w = <-77 , 28>
∴ 4v - 7w = <24 - -77 , -8 - 28>
∴ 4v - 7w = <101 , -36>
# 11u + 3w
∵ u = <-5 , 7>
∴ 11u = <-55 , 77>
∵ w = <-11 , 4>
∴ 3w = <-33 , 12>
∴ 11u + 3w = <-55 + -33 , 77 + 12>
∴ 11u + 3w = <-88 , 89>
Answer:

Step-by-step explanation:
We are given that:

Where A and B are positive acute angles.
And we want to find cos(A + B).
Recall that cosine is the ratio of the adjacent side to the hypotenuse. Using this information, find the opposite side with respect to Angle A:

Tangent is the ratio of the opposite side to the adjacent side. Find the hypotenuse with respect to Angle B:

In summary:
With respect to Angle A, the adjacent side is 20, opposite is 21, and the hypotenuse is 29.
With respect to Angle B, the adjacent side is 60, the opposite is 11, and the hypotenuse is 61.
We can rewrite our expression as:

Using the above information, substitute in the appropriate values. Note that since A and B are positive acute angles, all trigonometric values will be positive. Hence:

Simplify:

You put the -16 - 7 in parenthesis and then the 4 infront of that. So the equation will look like 4(-16 - 7) = -92