These are all equations that can be solved by expanding and simplifying both sides of the equation:

1) (3х+5)(4х-1) = 12x^2 + 12x - 5
(6х-3)(2х+7) = 12x^2 + 36x - 6

Since both sides of the equation simplify to the same expression (12x^2 + 12x - 5), the equation is true for all values of x.

2) (5х-1)(2-х) = 10 - 7x - x^2
(х-3)(2-5х) = 10 - 7x - x^2

Since both sides of the equation simplify to the same expression (10 - 7x - x^2), the equation is true for all values of x.

3) (5х+1)(2х-3) = 10x^2 - 15x + 2x - 3
(10х-3)(х+1) = 10x^2 + 10x - 3x - 3

Since both sides of the equation simplify to the same expression (10x^2 - 15x + 2x - 3), the equation is true for all values of x.

4) (7х-1)(х+5) = 7x^2 + 35x - x - 5
(3+7х)(х+3) = 7x^2 + 21x + 3x + 9

These two sides do not simplify to the same expression, so this equation is not true for all values of x.