Question

if x + 1/x =7 then find the value of x³+1/x³
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Answer 1

Answer:

(x+1/x) ^3 = 7^3

x^3 +(1/x^3)+3x.1/x.(x+1/x) = 343

x^3 + (1/x)^3 +21 = 343

x^3 + (1/x)^3 = 321

Therefore, 321 is the answer

Step-by-step explanation:

Thank you

Answer 2

Answer:

Hallo

Given,

x + 1/x = 7---(1)

we know that, a³+b³ = (a+b)³-3ab(a+b)

Put the value,

x³+1/x³ = (x+1/x)³-3(x+1/x)

= (7)³-3*7

= 343-21

= 322

So, the value of x³+1/x³ = 322

I hope it may help you.

Good bye.