Formula use: \left(a-b\right)^3=a^3-3a^2b+3ab^2-b^3
Explanation
Here, given expression is : 3x-5
Now, Find the cubes of :
\left(3x-5\right)^3
\rightarrow\left(3x\right)^3-3.\left(3x\right)^2.5+3.3x.\left(5\right)^2-\left(5\right)^3
\therefore {27x}^3-135x^2+225x-125
Ans: {27x}^3-135x^2+225x-125\ .