Question

If one of the factor of x²+x-20 is (x+5) find other factor​

Answer 1

(x - 4)

Explanation:

METHOD 1 (Long Division Method):-

[See the attachment for full solution of Method 1]

One factor of x² + x - 20 is already given. To find the other factor , divide the polynomial with the factor and the quotient you'll get after dividing will be the second factor of the polynomial.

METHOD 2 (Factorising) :-

Factorise x² + x - 20.

• Split the middle terms.

`=> x^2 + 5x - 4x - 20`

• Take 'x' common from first two terms and take '-4' common from last two terms.

`=> x(x + 5) - 4(x + 5)`

• Take '(x+5)' whole common from the expression.

`=> (x + 5)(x - 4)`

(x + 5) & (x - 4) are the factors of x² + x - 20.

Answer 2

Explanation:

x^2+x-20

=x^2-(5-4)x-20

=x^2-5x+4x-20

=x(x-5)+4(x-5)

=(x-5)(x+4)

therefore the other factor is (x+4)