#### Question

Expand.

(13+x) (13−x)

#### Solution

(13+x) (13−x)

= -[(x+ 13)(x - 13)]

= - [(x)^{2} + {13 + (-13)}x + (13) × (-13)]

= -[x^{2} + (13-13)x - 169)]

= -[x^{2} - 169]

= 169 - x^{2}

Is there an error in this question or solution?

Solution Expand. (13+X)(13−X) Concept: Expansion of (X + A) (X + B).