(−6)∙(a+2b−3c−4d)−(−2)∙(−4a−3b+2c+d ) simplify asap

An architect is designing a water fountain for a park she uses the given function to model the water jet flowing from the fountain nozzles where h(x) gives the height of the water jugs in feet x feet from the starting point h(x)=-1/20x+x+15

Which point lies on a circle with a radius of 5 units and center at p(6, 1)?

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.