As it says in the title.
- anything not explicitly allowed is forbidden.
- use 3, 3, 5, 7 and multiplication, division, sum, difference, unary minus, and exponentiation in any order. Parentheses are allowed for grouping.
- factorials, square roots, concatenation and decimal points are forbidden.
- lateral thinking is forbidden.
- must give three distinct expressions. No partial answers, please.
If it were 3, 5, 5, 7 instead of 3, 3, 5, 7 then you could do
Clarification: What is distinct? Or rather, what is not distinct:
5x(-3+7)x5 - same as 2. (-3)x(-5)x7-5 - same as 3.
Attribution: conceived by myself