Please help I need this answer and will mark branliest and give thanks

1. preform the indicated operation. then estimate to see whether the proposed result is reasonable. 811.1 - 8.039 803.071 803.061 803.161 831.061 2. the ordered pair (1, 2) lies in which quadrant? quadrant ii quadrant iv quadrant iii quadrant i 3. sean tries to drink 3 liters of water every day how my millimeters of water does he drink in a day? 0.3 ml 0.003 ml 3,000 ml 30 ml 4. find the least common multiple. (lcm). 10, 36 5 180 20 360

If x = 12 and y = 3, what is the value of x - y 2? 81 6 3 18

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.