Respuesta :

Answer:

a. 2x -3

b. 7

Step-by-step explanation:

a. The expression that represents the difference is sales between the two sales will be:

9x - (7x + 3) = 9x - 7x - 3 = 2x - 3

b. What we do here is to simply substitute the value of 5 for x

mathematically, we have to substitute the value of 5 in the expression above

We have this as:

2(5) -3

= 10-3 = 7