I have a to write the mathematical formulas corresponding to the following statements with the help of the following signs only: propositional connectives, quantifiers, variables varying through set $\mathbb{N}$ or $\mathbb{R}$ and symbols indicated in brackets.
$1)$ even numbers have no odd multiples $(·,+,=,1)$ - variables varying through set $\mathbb{N}$
$2)$ there is no largest negative number $(<, 0, =)$ - variables varying through set $\mathbb{R}$
$3)$ number $x$ is a product of an odd number and a prime number $(·, +, =, 1)$ - variables varying through set $\mathbb{N}$
$4)$ $x$ is the only smallest square bigger than $n(·, +, =, 1, <)$ - variables varying through set $\mathbb{R}$
I am not sure how to write the whole formula such that it is correct and fulfills the needs of the given task. If someone could explain to me how to write such formulas, I would be very grateful.