Question

lets write the value of x³+1/x³ by calculation if x+1/x=5​

Answer 1

Answer:

if x+1/x=5

$(x + 1 \div x) ^{3} = (5)^{3} = x^{3} + 1 \div x^{3} + 3xy(x + y) \\ 125 = x {}^{3} + 1 \div x {}^{3} + 3x \div x(5) \\ 125 = x {}^{3} + 1 \div x {}^{3} + 15 \\ {x}^{3} + {y}^{3} = 125 - 15 = 110$

thank you