Evaluate the expression 7+4b when b= 3

We can substitute 4b with 12, because 4 * 3 = 12. 4b is the same as 4 different b's, and when we know b is 3, we can multiply 4 by 3 to get 12.

7 + 4b =

7 + 4 * 3 =

7 + 12 =

19.

7 + 4b when b = 3 is 19.

  5

Step-by-step explanation:

80 tiles in 8 equal rows means there are 80/8 = 10 tiles in each row. If half the tiles in a row are blue, there are 10/2 = 5 blue tiles in each row.