Answer:
31
Step-by-step explanation:
Following PEMDAS: Do the division first followed by the subtraction.

Answer:
The answer is 1
Step-by-step explanation:
14 = 2 × 7
51 = 3 × 17
21 = 3 × 7
Answer:
4
Step-by-step explanation:
To know the scale factor here, just know that 16/4 = 4, and 8/2 = 4 too, so the scale factor is 4.
Just that the respective sides need to have the same ratio.
Note, if it was from B to A, it'd be 1/4.