3x²-5x-4+xy-(2xy+2x²) Simplified is x²-5x-4-xy
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Average speed = (distance final - distance initial)/(time final - time initial)
Average speed = (30-0)km /(100 -0)min = 3/10 km/min
3/10 km/min *60 min/1 h = 180/10 km/h= 18 km/h
In Graph x-axis represents number of visits and y-axis represents cost.
As graph comes up to be a linear one, so we can clearly say that cost is increasing linearly in multiples of 5.5 with increase in number of visits.
Example :
If museum is visited once then cost (y) = 5.5 x 1 = 5.5
If museum is visited twice then cost (y) = 5.5 x 2 = 11
If museum is visited thrice then cost (y) = 5.5 x 3 = 16.5
... cost (y) goes on in creasing when number of visits (x) increase with multiples of 5.5
If the sample is random, it is not valid.