work. Do not solve.
-5x + 9y = -12
-4x - 4y = -32
A) Substitution B) Addition
Answer: B
Write the word or phrase that best completes each statement or answers the question.
-In a chemistry class, 9 liters of a 4%-saline solution must be mixed with a 10% solution to get a 6% solution. How many liters of the 10% solution are needed?
A) 3.5 L
B) 4.5 L
C) 5.5 L
D) 9.0 L

Question

Quizplus · Accepted Answer

To solve this problem, we can use the equation:

0.04(9) + 0.1(x) = 0.06(9 + x)

Where x is the number of liters of 10% solution needed.

Simplifying and solving for x, we get:

0.36 + 0.1x = 0.54 + 0.06x

0.04x = 0.18

x = 4.5

Therefore, we need 4.5 liters of the 10% solution.

Work. Do Not Solve