Answer:
71 remainder 80
Step-by-step explanation:

Y=9-2x, 9-2x=0, 2x=9, x=9/2, if you were asked to put it in standard form put down the first thing I said, if you were asked for solution then everything I said
If u add them all up and multiple by two in total he walks 43 blocks
Find the volumes of each separate rectangular prism, (top) 9 x 4 x 12 = 432 cubic meters, (bottom) 10x2x2 = 40 cubic meters, and then add them together to get the overall volume, 40+432 = 472 cubic meters. the strategy is using length times width times height, LxWxH.