On the right side, there are
• 2•2 = 4 atoms of Nb
• 2•5 = 10 atoms of O
so among the reactants on the left, the reaction is balanced as
4 Nb + 5 O₂ → 2 Nb₂O₅
Step-by-step explanation:
We need to find each of the following as a rational number in the form of p/q
(a) (3/7)² (b) (7/9)³ (c) (-2/3)⁴
Solution,
(a) (3/7)²

(b) (7/9)³

(c) (-2/3)⁴

Hence, this is the required solution.
The answer is A.Use a compound interest calculator. Multiple sites to use. For me, I had to use my head for a while