Answer:
3
Step-by-step explanation:
Using listing:


No other factors are possible.
Hence, 1, 3, 7 and 21 are factors of 21.
3(y-7)
use distributive property
It would be 1,200 because you just have to multiply 400 times 3 hope it helped :)
First side is = x
Second side is = 3x-3
Third side is = 44x - 66
Perimeter = Sum of sides
P = x + 3x + 44x -66 -3
P = 48x - 69