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2 years ago

Review the following information about vectors q and r.

Mathematics

2 answers:

Vitek1552 [10]2 years ago

7 0

<h3>Answer: a = -1 (fourth choice)</h3>

==========================================

Work Shown:

q = (-4, 1) is one vector

r = (a,3) is another vector

The resultant vector is

q+r = (-4,1)+(a,3)

q+r = (-4+a,1+3)

q+r = (-4+a,4)

Multiply both sides by 7

7(q+r) = 7*(-4+a,4)

7(q+r) = (7*(-4+a),7*4)

7(q+r) = (-28+7a, 28)

---------------

Since 7(q+r) = (-35, 28), we know that,

(-28+7a, 28) = (-35, 28)

which leads to

-28 + 7a = -35

when we equate the x components of each vector. Let's solve for 'a'

-28 + 7a = -35

7a = -35+28

7a = -7

a = -7/7

a = -1

--------------

Check:

q = (-4,1)

r = (a,3) = (-1,3)

q+r = (-4,1)+(-1,3)

q+r = (-4+(-1), 1+3)

q+r = (-5, 4)

7*(q+r) = 7*(-5, 4)

7*(q+r) = (7*(-5), 7*4)

7*(q+r) = (-35, 28)

The answer is confirmed.

sladkih [1.3K]2 years ago

5 0

Answer:

D. -1

Step-by-step explanation:

edge test

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