Question

PLZZZ HELP ASAP!!!!!!!

Marie mixes 16 liters of 18% acid solution with a 27% acid solution, which results in 21% acid solution. Let x represent the number of liters of 27% solution used and let y represent the number of liters of mixture. Which system of equations can be used to find the number of liters of 27% acid solution in the mixture?

1. y = x + 16; 0.27y = 0.21x + 2.88

2. y = x + 16; 0.21y = 0.27x + 2.88

3.y = x + 16; 0.21y = 0.27x + 4.32

4. y = x + 16; 0.27y + 2.88x = 0.21

Answer 1

2. y = x + 16; 0.21y = 0.27x + 2.88

Explanation:

You have two conditions:

• Volume of 18 % + volume of 27 % = volume of 21 %
• Mass of acid in 18 % + mass of acid in 27% = mass of acid in 21 %

For the first condition,

16 + x = y Transpose

(1) y = x + 16

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For the second condition

V₁c₁ + V₂c₂ = V₃c₃

16×0.18 + 0.27x = 0.21y

2.88 + 0.27x = 0.21y Transpose

(2) 0.21y = 0.27x + 2.88

The system of equations is y = x + 16; 0.21y = 0.27x + 2.88