Question 1119968
200x + 700y = 900(0.14)
300x + 900y = 1200(0.145
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200x + 700y = 126 (1) multiply all sides times -1.5 and add to (2)
300x + 900y = 174 (2)
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300x + 900y = 174
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-300x + -1050y = -189
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0x + -150y = -15; y = -15/-150 = 0.1 = 10%
The concentration of the second solution is 10%
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200x + 700(0.1) = 126
200x + 70 = 126
200x = 56
x = 0.28
The concentration of the first solution is 28%
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Let's see if this is true:
200x + 700y = 126; 200(.28) + 700(.1) = 126; 56 + 70 = 126 Correct
300x + 900y = 174; 300(.28)+ 900(.10) = 174; 84 + 90 = 174 Correct