(a)
To find the original percent concentration of salt, we need to substitute x = 0 into the function P(x).
P(0) = (100*0 + 100) / (0 + 10)
P(0) = 100 / 10
P(0) = 10
Therefore, the original percent concentration of salt is 10%.
(b)
To find the percent concentration of salt after 10 more grams of salt are added, we need to substitute x = 10 into the function P(x).
P(10) = (100*10 + 100) / (10 + 10)
P(10) = 1100 / 20
P(10) = 55
Therefore, the percent concentration of salt after 10 more grams of salt are added is 55%.