SOLUTION: Find the indicated quantity, assuming that u = 5i + j, v = i − 3j, and w = 3i + 7j. u · (v + w)

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Question 1206885: Find the indicated quantity, assuming that
u = 5i + j, v = i − 3j, and w = 3i + 7j.
u · (v + w)
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

u+=+5i+%2B+j
v+=+i+-+3j
w+=+3i+%2B+7j

u%2A%28v%2Bw%29
first find v%2Bw=i-3j%2B3i%2B7j=4i%2B4j

u%2A%28v%2Bw%29=%285i+%2B+j%29%2A%284i%2B4j%29
u%2A%28v%2Bw%29=5i%2A4i%2B5i%2A4j%2Bj%2A4i%2Bj%2A4j

since i%2Ai+=+1, j%2Aj+=1, i%2Aj+=+0,+j%2Ai+=0, we have

u%2A%28v%2Bw%29=5%2A4%2A1%2B5%2A4%2A0%2B0%2A4%2B1%2A4
u%2A%28v%2Bw%29=24