We'll use the FOIL method to multiply the factors.
FOIL
First, Outside, Inside, Last
Multiply the first terms, then the outside terms, then the inside terms, then the last terms.
First
<span>
(2r – 5)
(r + 10)
</span>

<span>
Outside
</span><span>(
2r – 5)(r +
10)
</span>

<span>
Inside
</span><span>(2r
– 5)(r + 10)
</span>

<span>
Last
</span><span>(2r
– 5)(r +
10) </span>

<span>
The trinomial should now look like this:
</span>

<span>
Combine like terms:
</span>

<span>
The following trinomial will be your answer:
</span>

<span>
</span>