If x+1÷x=5 then x cube + 1÷x cube =?
Answers
Answered by
0
x + 1/x = 5
now
x³ + 1/x³
= (x + 1/x )³ - 3x/x.(x+1/x)
= 5³ - 3×5
= 125-3×5
= 110
now
x³ + 1/x³
= (x + 1/x )³ - 3x/x.(x+1/x)
= 5³ - 3×5
= 125-3×5
= 110
mehsheed59:
Answer is not 122 because it is not there in given options
Sorry my mistake will you keep - in + places in the question and solve it again
x³ + 1/x³
= (x + 1/x )³ - 3x/x(x+1/x)= 5³ - 3*5
= 125-3*5
= 110
= (x + 1/x )³ - 3x/x(x+1/x)= 5³ - 3*5
= 125-3*5
= 110
i think this is correct
yes
Answered by
0
at first , note that, x^3+x^-3=(x+1/x)^3-3*(x+1/x). now put the values.
125-3*5=110
125-3*5=110
Similar questions