(a+b-c)3 formula
State formula
Answers
Answered by
4
Step-by-step explanation:
a²+b²+2ab=(a+b)²
a²+b²-2ab=(a-b)²
a²-b²=(a+b)(a-b)
a³+b³=(a+b)(a²+b²-ab)
a³-b³=(a-b)(a²+b²+ab)
a³+b³+c³-3abc=(a+b+c)(a²+b²+c²-ab-bc-ca)
a³+b³+3ab(a+b)=(a+b)³
a³-b³-3ab(a-b)=(a-b)³
(a+b-c)³=a³+b³-c³+3(a+b)(b-c)(a-c)
Answered by
7
Given,
(a+ b - c)³
To find,
The formula.
Solution,
So we know that
a² + b² + 2ab = (a+b)²
Which means
a² + b²- 2ab = (a-b)²
a²- b² = (a + b)(a - b)
Then,
a³+ b³ = (a + b)(a² + b² - ab)
a³- b³ = (a - b)(a² + b² + ab)
a³ + b³ + c³- 3abc = (a + b + c)(a² + b² + c² - ab - bc - ca)
a³ + b³ + 3ab(a + b) = (a + b)³
a³- b³ - 3ab(a - b) = (a - b)³
(a+ b - c)³ = a³ + b³- c³ + 3(a + b)(b - c)(a - c)
Thus, (a+ b - c)³ = a³ + b³- c³ + 3(a + b)(b - c)(a - c)
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