Respuesta :

Answer:

A. 4(4a + 18)

B. 8(2a + 9)

Step-by-step explanation:

We know that :

16a = 4×4×a

72 = 4×18

Then

16a + 72 = 4×(4a) + 4×(18)

              = 4 × (4a + 18)

On the other hand,

16a = 8×2×a

72 = 8×9

Then

16a + 72 = 8×(2a) + 8×(9)

              = 8 × (2a + 9)