It appears that you have here a list of the # of minutes spent each day on HW, and that y ou need to sum up this list to answer the question. Unfortunately I cannot read the last numeral.
The answer (assuming that my guess is correct) would be found as follows:
Total hours spent on HW in one week = (18+20+22+11+19+18+ ?? )
Answer:
W is not a subspace.
Step-by-step explanation:
Notice that (-1,2,2) and (-1,5,3) are both elements of W. Because its x coordinate, x = -1, satisfy the condition |x| = 1.
but (-1,2,2) + (-1,5,3) = (-2,7,5) do not belongs to W. Because its first coordinate, x =-2, do not satisfy |x| = 1.
960 watts = 24 hours
4 days = 96 hours
960 (watts) x 4 (days) = 3840 watts
12 hours= 480 watts
6 hours = 240 watts
18 hours = 720 watts
3840 (4 days) + 720 (18 hrs) = 4560