8. 6m + 3n
11. 8r^3 - r^2
12. 3h^2 + 8
hope this helps !
percent ---------------- quantity
Acid type I 60.00% ---------------- x liters
acid type II 30.00% ------ 60 - x liters
Mixture 40.00% ---------------- 60
Total 60 liters
60.00% x + 30.00% ( 60 - x ) = 40.00% * 60
60 x + 30 ( 60 - x ) = 2400
60 x + 1800 - 30 x = 2400
60 x - 30 x = 2400 - -1800
30 x = 600
/ 30
x = 20 liters 60.00% Acid type I
40 liters 30.00% acid type II
brainliest plzz
Answer:

Step-by-step explanation:
Given that,
The side length of a square, l = (x+4) inches
We need to find an expression to represent the area of the square.
The area of a square is given by :

So,

So, the area of the square is
.