Question

Is f(x)=x(x+5) a linear function?

Answer 1

Let us expand that


`\sf f(x)=x(x+5)`

`\sf f(x)=x^2+5x`

Since it has
`\sf x^2` in it, it is now a linear function.

So the answer is
`\sf \boxed{No, ~this~ is~ not~ a ~linear ~function.}`

Answer 2

f(x)= x(x+5)
= x²+5x
this is not a linear function as it is not in the form y=mx+b
it is a quadratic function with x intercepts at 0 and -5 and y intercept 5