Answer:
A.
Step-by-step explanation:
1. Take out the constants
-(2 x 3 x 4 x 2)xxyy^3
2. Simplify 2 x 3 x 4 x 2 to 48
-48xxyy^3
3. Use Product Rule: x^ax^b = x^a+b
-48x^1+1y^1+3
4. Simplify 1 + 1 to 2
-48x^2y^1+3
5. Simplify 1 + 3 to 4
-48x^2y^4
<span>calcium hydride + water → calcium hydroxide + hydrogen</span>
