Let the number of matinee tickets they bought be t, the number of drinks bought be d and the number of popcorn bags bought be p, then the amount the spend on the number of drinks and bags of popcorn they bought is given by 
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The coefficients in the expression are 5.5 and 6 while the constant is 13 and the variables are d and p.
The coefficients in the expression are 5.5 and 6 while the constant is 13 and the variables are d and p.