When two lines intersect to form a 90 degree angle, these lines are called perpendicular lines.
The answer to the question is d
Answer:

first create a bracket:

then solve the first bracket:

then open the remaining bracket:

carryout the subtraction operation:

If you would like to solve <span>(8r^6s^3 – 9r^5s^4 + 3r^4s^5) – (2r^4s^5 – 5r^3s^6 – 4r^5s^4), you can do this using the following steps:
</span>(8r^6s^3 – 9r^5s^4 + 3r^4s^5) – (2r^4s^5 – 5r^3s^6 – 4r^5s^4) = 8r^6s^3 – 9r^5s^4 + 3r^4s^5 – 2r^4s^5 + 5r^3s^6 + 4r^5s^4 = 8r^6s^3 – 5r^5s^4 + r^4s^5<span> + 5r^3s^6
</span>
The correct result would be 8r^6s^3 – 5r^5s^4 + r^4s^5<span> + 5r^3s^6.</span>
I think its c yo...............