Answer:
pqr²+pr-rp²+rq²
Step-by-step explanation:
pq(r²+1)-r(p²+q²)
pqr²+pr-rp²+rq²
5x-7x=-8
-2x=8
x=-4
this is how to solve it
Answer:

Step-by-step explanation:
Theoretically, there is not square root of neither 13 nor a negative number so the special symbol is used to represent the square root of a number.
The answer is A, not sure about the expression though. Sorry
400,7,000 i think im not quit sure i dont know