Asmall pump can drain a pool in 9 hours. a large pump could drain the same pool in 7 hours. how long will it take to drain the pool of both pumps are used simultaneously

Me figure out the process to determine x you appreciate it : )

The graph shown below expresses a radical function that can be written in the form f(x)=a(x+k)1/n+c what does the graph tell you about the value of n in this function

What is the equation of the following graph in vertex form? parabolic function going down from the left through the point zero comma twelve and through the point two comma zero and turning at the point four comma negative four and going up through the point six comma zero and continuing towards infinity courtesy of texas instruments a: y = (x − 4)2 − 4 b: y = (x + 4)2 − 4 c: y = (x + 2)2 + 6 d: y = (x + 2)2 + 12