Answer:
Following are the responses to the given question:
Step-by-step explanation:
For point A:

For point B:
{x | x is the positive square number less than or equal to 81}
For point C:
All given sets were equal and equal, that since elements and the element no. are identical.
Answer:
x = - 4
Step-by-step explanation:
Hi there !
if f(x) = 2x + 7 and f(x) = -1 =>
2x + 7 = - 1
2x = - 1 - 7
2x = - 8
x = - 8 ÷ 2
x = - 4
Good luck !