Question

Can someone explain how to do this, please?​

Answer 1

`\sqrt{ {28x}^(2) - 6x }`

Explanation:

You would substitute "2x" for every "x" in the function in the same way you would substitute any other number.

So if f(x)=Sqrt[7x²-3x], then: f(2x)=Sqrt[7(2x)²-3(2x)]

=Sqrt[7(4x²)-3(2x)]

=Sqrt[28x²-6x]