Describe lengths of three segments that could not be used to form a triangle. segments with lengths of 9 in., 9 in., and 4,9,15,1,9 in. cannot form a triangle.

answer choices; 4 9 15 1 9 5

I don't understand, but, two form a triangle your two SHORTEST sides have to equal LARGER than your LONGEST side. Example: 2,3,4
The two shortest sides are 2 and 3. 2+3=5 Is the sum greater than the largest side,4,? Yes, therefore it makes a triangle.

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction