It’s on probability please help

In the following diagram it is given that dec,ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Can someone me with my math problems i have a bunch. i will give brainliest and lots of pleeeaaasssee