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If a- 2b +3c =0 prove that a³ -8b³+ 27c²= - 18abc​
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If a- 2b +3c =0 prove that a³ -8b³+ 27c²= - 18abc​

User Marcus Recck
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2 Answers

3 votes

Explanation:

the answer is in the photo as attached

If a- 2b +3c =0 prove that a³ -8b³+ 27c²= - 18abc​-example-1
User Erbureth
by
7.6k points
1 vote

Answer:

Use the identity:

  • x³ + y³ + z³ = 3xyz if x + y + z = 0

Substitute:

  • x = a, y = -2b, z = 3c

to get

  • a³ + (-2b)³ + (3c)³ = 3a(-2b)(3c)
  • a³ - 8b³ + 27c³ = --18abc
User Cltsang
by
8.4k points
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