Answer:

Step-by-step explanation:
Let the unknown be x
The product of the number and 7 more than 5 is expressed as 7x + 5
If this no more than 21, then 7x + 5 must be less than or equal to 21 as shown;

Hence the product of a number and 7 more than 5 is no more than 21 is expressed as 7x+5 <= 21