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PRE CAL

Let a = 2i + 9j, b = –4i + 5j, c = i – 3j, and d = 14j where i and j are unit vectors.

What is (a – b) – (2d – c) in terms of i and j?

5i – 27j
5i + 35j
7i – 27j
7i + 39j

Respuesta :

mhanifa

Answer:

  • 7i - 27j

Step-by-step explanation:

Given

  • a = 2i + 9j, b = –4i + 5j, c = i – 3j, d = 14j

To find

  • (a – b) – (2d – c)

Solution

  • (a – b) – (2d – c) =
  • 2i + 9j - (–4i + 5j) - (2(14j) - (i – 3j)) =
  • 2i + 9j + 4i - 5j - 28j + i - 3j =
  • (2 + 4 + 1)i + (9 - 5 - 28 - 3)j =
  • 7i + (-27)j =
  • 7i - 27j

Answer:

C

Step-by-step explanation:

EDGE

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