Hi everyone how are you today i have some question about congruence and i don’t understand can you me .

You can understand this by two ways

1) through congruency rules

It says that triangle ABE is congruent to DCE
So the corresponding angles are equal
Eg
Angle A to Angle D
Angle B to angle C
Angle E to angle E

So they’re asking the angles AEB and DEC (which are equal as per congruency)

Thus you can equate them
4y-15=69
y=21

2) through vertically opposite angles
Since the triangles’ angles are vertically opposite one another, they are equal.

Then you can equate them the same way

Hope this helped!!

31 is prime. and it’s prime factorization is just 31.