I need help on both can u help me

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;

Neveah and clint are baking muffins for the bake sale. they need to bake 30 muffins for their display case. clint has baked 4 so far, and neveah has baked 7. how many muffins (m) do they have left to bake? show your work!

One integer is 8 times another. if the product is 72, then find the integers