(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca): find the missing part
This type of question, asked 6 times: 14 Jul 2023 S1, 17 Jul 2023 S3, 18 Jul 2023 S2, 18 Jul 2023 S4, 20 Jul 2023 S2, 26 Jul 2023 S2. All 6 questions below, oldest first.
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Question 1
14 Jul 2023 S1
72If (a+b+c)=16, and (a2+b2+c2)=90, find the value of (ab+bc+ca).
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Question 2
17 Jul 2023 S3
52What is the value of the given expression?
(a+b+c)2−a2−b2−c2
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Question 3
18 Jul 2023 S2
68If (a+b+c)=19, and (a2+b2+c2)=155, find the value of (a−b)2+(b−c)2+(c−a)2.
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Question 4
18 Jul 2023 S4
52If a+b+c=6 and a2+b2+c2=14, then what is the value of (a−b)2+(b−c)2+(c−a)2?
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Question 5
20 Jul 2023 S2
67If x + y + z = 4 and x2+y2+z2=12, then find xy + yz + xz.
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Question 6
26 Jul 2023 S2
63If (a+b+c)=13, and (ab+bc+ca)=54, find the value of (a2+b2+c2).
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