Abox contains a collection of triangular and square tiles. there are 25 tiles in the box, containing 84 edges total. how many square tiles are there in the box?

X=number of triangular tiles.
y=number of squiare tiles.
we suggest this equiations system.
x+y=25
3x+4y=84
we solve this equiations system by substitution method.
x=25-y
3(25-y)+4y=84
75-3y+4y=84
y=84-75
y=9

x=25-y
x=25-9=16

Solution: we have 16 triangular tiles and 9 squiare tiles.

Aand b is what i think

You didn’t put the necessary image to solve the question : p