Question

What is the expression obtained when rs−4st−12s is subtracted from 8rs−9st+15s and then the difference is added to 8rs+5st−7s?

Answer 1

Answer is 15rs + 20s

Step by step in the attachment

8rs -9st + 15s
- 1rs -4st -12s
____________
7rs -5st + 27s

+ 8rs +5st -7s
___________

15rs + 20s