MR-693 / 1.

Which of the following sentences are statements?

a) *1+1 = 2*

b) the number *16* is an odd number

c) an even number can be written in the form *2n*, where *n* is a natural number

d) the solution of the equation *3x=18* is a natural number

e) *( a-b)*^{2 }≥ 0 for every rational *a* and *b*

f) *ab > 0* if *a* and *b* are of the same sign

g) *a*^{2 }> 0 if *a* is a negative number

h) *- a*^{2} < 0 if *a* is a negative number