9. a chemistry teachers needs 25 liters of a 12% salt solution. the teacher has mixture of a 5%
salt solution and a mixture of a 20%, salt solution. how many liters of the 5% and 20% mixture
should she mix to get what she needs? round your answer to the nearest tenth if necessary. be
sure to write down your equation (equation: 2 pts, solution: 2 points, 1 pt)

13.3 L of 5% salt solution and 11.7 L of 20% salt solution

Step-by-step explanation:

Let

x L = amount of 5% solution

y L = amount of 20% solution.

1. A chemistry teachers needs 25 liters of salt solution, then

2.  A chemistry teachers needs 25 liters of a 12% salt solution, so there are

liters of salt.

Amount of salt in 5% solution liters

Amount of salt in 20% solution liters,

thus

3. Solve the system of two equations:

From the first equation,

Substitute it into the second equation:

the barter

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.