Answer:
it's −32
Step-by-step explanation:
my bad if u get it wrong or anything
For this case we have the following system of equations:

We multiply the first equation by -1:

We have the following equivalent system:

We add the equations:

Equality is not fulfilled, so the system of equations has no solution.
Answer:
Option C
Think the 4 less than but not equal to as a equal sign
step 1. isolate the variable ( variable must stand alone)
step 2. subtract 12n -12n=0
step 3. since you subtract 12n from the left you must do the same to the right.
step 4. 13n - 12n =1n
step 5. the equation should look like this -4 less than but not equal to 1n
step 6. isolate the variable n
step 6. divide 1n/1 on the right and on the left -4/1 it equals -4
so, n is -4
Your formula here is A=pir^2
Plug in the numbers but instead use 22/7 for pi
A=(22/7)(21)^2
A=22/7*441=1386
Answer is 1386 sq inches