WILL GIVE BRAINLIEST 36 POINTS Please show the steps.
Which linear system of equations does the matrix represent M=[87|4] [20|5]
A. 8x+7y+4z=0
2x+0y+5z=0
B. 8x+7y=4
2x+0y=5
C. 8x-7y-4z=0
2x+0y+5zz=0
D. 8x+7y=-4
2x+0y=-5

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours