Answer: Its B
Step-by-step explanation:
The 63 is the err in her explanation here.
You replace x with 3 and y with -2 so
3-3(-2)=9
the answer is D.9
Let x(t) = the length of a side of the square (cm) at time t (s).
The rate of change of x is given as

The area (cm²) at time t is
A = x²
The rate of change of the area with respect to time is

When A = 9 cm², then x = √9 = 3cm. Hence obtain

Answer: 12 cm²/s