Algebra-2

According to the Rational Root Theorem, for a polynomial equation , the possible rational roots are of the form , where is a factor of the constant term and is a factor of the leading coefficient .

For the equation , the leading coefficient is 1 and the constant term is 40.

Factors of 40 are ±1, ±2, ±4, ±5, ±8, ±10, ±20, ±40.

So the possible rational roots are ±1, ±2, ±4, ±5, ±8, ±10, ±20, ±40.

Now we test these possible roots one by one.

Testing :

Substitute into the equation: