You're asking for the equation of the reaction between formaldehyde, benzaldehyde, and acetone. However, there is no direct, single-step reaction between these three reagents.

Here's why and some potential reactions that could occur:

* Formaldehyde (HCHO) is highly reactive: It readily undergoes condensation reactions, especially with itself (to form polymers like paraformaldehyde) or with other aldehydes or ketones.

* Benzaldehyde (C6H5CHO) and acetone (CH3COCH3) can also react: Benzaldehyde can react with acetone in the presence of a base (like NaOH) to form a condensation product called dibenzalacetone. This reaction is known as the Claisen-Schmidt condensation.

Therefore, there's no single equation for the reaction of all three reagents together. However, we can write separate equations for the possible reactions:

1. Formaldehyde with itself (polymerization):

* nHCHO → (HCHO)n (where 'n' is the degree of polymerization)

2. Formaldehyde with benzaldehyde (Cannizzaro reaction):

* HCHO + C6H5CHO + NaOH → HCOONa + C6H5CH2OH (This is a disproportionation reaction, where one molecule is reduced and another is oxidized.)

3. Benzaldehyde with acetone (Claisen-Schmidt condensation):

* C6H5CHO + CH3COCH3 → C6H5CH=CHCOCH3 + H2O

Important Notes:

* The conditions for each reaction are different.

* Other byproducts and side reactions might occur.

* You'd need to specify the desired reaction product to get a more accurate and relevant equation.

Let me know if you have a specific reaction in mind or if you'd like more information about any of the reactions mentioned!