Question

A scientist needs 10 liters of 20% acid solution for an experiment but she only has 5% soulition and a 40% solution ,to the nearest tenth of a liter about how many liters of 5% and the 40% solutions should she mix to get the solutions she needs , write and solve the equation to match

Answer 1

10 * .20 = .05 x + .40 ( 10-x)

5 5/7 liters of 5%

4 2/7 of the 40 %

Explanation:

we need 10 liter of a 20 % solution

We have x liters of 5% and since there is a total of 10 liters we have 10-x of the 40 % solutions

10 * .20 = .05 x + .40 ( 10-x)

2 = .05x +4 - .4x

Combine like terms

2 = 4- .35x

Subtract 4 from each side

2-4 = -.35x

-2 = -.35x

Divide by -.35

-2/.-35 =x

40/7 =x

5 5/7 =x

10 -5 5/7 = 4 2/7

4 2/7 of the 40 %