Update How_to_contribute.md

How_to_contribute.md

@@ -7,20 +7,24 @@ The TCO Calculator’s purpose is to assist users in comparing the deployment [T
 To do so, it computes the cost/request of said service and adds a labor cost to get a comprehensive estimate of how much the set-up of these services would cost.
 
 Here is the formula used to compute the cost/request of an AI model service:
-
+\\(CR = \frac{CIT_{1K} * IT + COT_{1K} * OT}{1000}\\)
 
 with:
-- CR = Cost per Request
-- CIT_1K = Cost per 1000 Input Tokens
-- COT_1K = Cost per 1000 Output Tokens
-- IT = Input Tokens
-- OT = Output Tokens
+- \\(CR\\) = Cost per Request
+- \\(CIT_{1K}\\) = Cost per 1000 Input Tokens
+- \\(COT_{1K}\\) = Cost per 1000 Output Tokens
+- \\(IT\\) = Input Tokens
+- \\(OT\\) = Output Tokens
 
 For instance, imagine we want to evaluate the cost of a summarization request. We will assume here that the number of input tokens is `500`, and that the output is `200` tokens.
 
 If we use OpenAI GPT3.5 pricing, prices are `$0.0015` per 1k input tokens, and `$0.002` per 1k output tokens.
 
-Therefore the formula gives us: Cost per request = (500 * 0.0015 + 0.002 * 200) / 1000 = $0.00115, aka `$1.15` per `1000` requests.
+Therefore the formula gives us: 
+
+\\(CR = \frac{0.0015 * 500 + 0.002 * 200}{1000}\\)
+
+so \\(CR = $0.00115\\), aka `$1.15` per `1000` requests.
 
 
 ## Contributing