if a+b =11,ab =28 find the value of a^3+b^3
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Answered by
139
a³ + b³ = (a + b) (a² - ab + b²)
a³ + b³ = 11 . (a² + b² - 28)
a³ + b³ = 11 ((a + b)² - 2ab - 28)
a³ + b³ = 11 (121 - 2 . 28 - 28)
a³ + b³ = 11 . 37
a³ + b³ = 407
a³ + b³ = 11 . (a² + b² - 28)
a³ + b³ = 11 ((a + b)² - 2ab - 28)
a³ + b³ = 11 (121 - 2 . 28 - 28)
a³ + b³ = 11 . 37
a³ + b³ = 407
Answered by
54
Let a=4 ,b = 7
then a+b= 4+7=11. & ab= 4×7=28
a³+b³= (a+b)(a²-ab+b²)
43+73 = (4+7) (42 -28 +72)
= 11× (16 -28 +49)
= 11× (-12+49)
= 11× 37
= 407
then a+b= 4+7=11. & ab= 4×7=28
a³+b³= (a+b)(a²-ab+b²)
43+73 = (4+7) (42 -28 +72)
= 11× (16 -28 +49)
= 11× (-12+49)
= 11× 37
= 407
dikshadhyani:
thx
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