First off, let's convert the percentages to decimal format, so our 77% turns to 77/100 or 0.77, and our 55% turns to 55/100 or 0.55 and so on
now, the sum of both salines, must add up to the 77% mixture, let's say is "y"
so, 11 + 4 = y, and whatever the concentration level is, must also sum up to the mixture's concentration of 77%
anyway thus

solve for "x"
Answer:
efghijklmnopqrstuvwxyz, thank me later
Its the identity property
Answer:
x = 1
Explanation:

Rule: log(a) + log(b) = log(ab)

cancel out log on both sides

relocate constant variable

take 3 as a common factor

divide both sides by 3

middle term split

factor common terms

collect into groups

set to zero

relocate variables

There must be a positive solution for log, so the solution is only x = 1
4000. 25000 x .16 is 4000