I hope this helps you
y=x^2-81
x^2=y+81
x=square root of y+81
f^-1 (x)= square root of x+81
The area of a square is its side length squared. So the side length of the square squared is 42, so the side length of the square is sqrt(42). The perimeter of the square is 4 times the side length, or 4sqrt(42), which is approximately 25.92.
Answer:
I would say 36
Step-by-step explanation:
because 4 ×5 is equals the 20
then 4×7 equals the 28
so 4×9 equals 36