The expression that represents the total number of customers held by all three companies is 5x + 10
Systems of equations are made of several equations with unknown variables.
Let the amount of customers company B has be x
If Company C has 10 customers more than company B, then the total customers for company B is x + 10
If Company A has three times as many customers as company B, the total customers for company A is 3x
Total customers = x + 10 + x + 3x
Take the sum
Total customers = 5x + 10
Hence the expression that represents the total number of customers held by all three companies is 5x + 10
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