Question

If x+y=10 and x-y=6 , what is the value of x³-y³​

Answer 1

`\huge\boxed{x^3-y^3=508}`

Explanation:

`\underline{+\left\{\begin{array}{ccc}x+y=10\\x-y=6\end{array}\right}\qquad|\text{add the sides of the equations}\\.\qquad2x=16\qquad|\text{divide both sides by 2}\\.\qquad\boxed{x=8}\\\\\text{Substitute it to the first equation}\\8+y=10\qquad|\text{subtract 8 from both sides}\\\boxed{y=2}\\\\x^3-y^3=8^3-2^3=512-8=504`