The distance, s = 40t₁ where t₁ is the time to complete the outward journey.
The same distance = vt₂ where t₂ is the time to complete the return journey at speed v.
For the whole journey, 2s=60(t₁+t₂). Therefore s=30(t₁+t₂)=40t₁=vt₂.
30t₁+30t₂=40t₁, 10t₁=30t₂, t₁=3t₂, so s=120t₂=vt₂ and v=120kph.
Do not click in the link above, the guy is a scammer, report his account to help others !
The expression can be simplified to a polynomial of degree 2.

<h3>
How to simplify the expression?</h3>
Here we have the expression:

We can directly simplify this by taking the variable as common factor:

This is a polynomial, as you can see, the maximum exponent is 2, so the degree of the polynomial is 2.
If you want to learn more about polynomials:
brainly.com/question/4142886
#SPJ1
I think this is more of an opinion than an actual answer