Question

Which of the binomials below is a factor of this trinomial? x² + 13x + 42

Answer 1

The given trinomial is,

`x^2+13x+42`

When we look at the trinomial, there is no number (coefficient) in front of

`x^2`

so we know that it is a simple trinomial. All you have to do in a simple trinomial is to find two numbers that not only add up to the b term, but multiply to the c term.

Here, b term is 13 and c term is 42

So two numbers that add upto 13 is, 6 and 7, 5 and 8, 11 and 2.

And the c term is 42. So two numbers that when multiplied gives 42 are,

6 and 7.

As this pair also is there in the b term, that is,

`6+7=13;6*7=42`

So, we can write, the given trinomial as,

`(x+6)(x+7)`

Thus, option c is the correct answer. SInce x+7