From the figure

Because they are linear angles
Then the first answer is right

Since l is parallel to m, then

Because they are interior supplementary angles

Because both of them = 180
Then answer 2 is right

Then

The last answer also is right
For answer 3
let us check it

Since angle 6 is common in the two sides, then we can cancel it from both sides, then

But no mention about that these two angles are equal, then we can not say they are equal
The wrong statement is answer 3