Can be written as a single fraction

Anyone know? is appreciated! will mark brainliest if correct!

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

The table below shows the approximate height of an object x seconds after the object was dropped. the function h(x)= -16x^2 +100 models the data in the table. for which value of x would this model make it the least sense to use? a. -2.75 b. 0.25 c. 1.75 d. 2.25