Answer:
35ml of the first brand
245ml of the second brand
Explanation:
The chef wishes to use two brands of an Italian dressing
The first brand constitutes of 7% vinegar
Let A represent the first brand
The second brand contains 15% vinegar
Let B represent the second brand
280 militers of dressing will be used to preoare both the first and second brands
A+B=280
The total mixture contains 14% vinegar, therefore it will be represented as
0.07A+0.15B= 0.14×280
0.07+0.15B= 39.2
We have to find the value of A and B inorder to get the amount of both brands.
0.07A+0.15B=39.2
0.07A+ 0.15(280-A)=39.2
0.07A+42-0.15A=39.2
Collect the co-efficient for both sides
0.07A-0.15B=39.2-42
-0.08A= -2.8
Divide both sides by -0.08
-0.08A/-0.08= -2.8/-0.08
A=35
To find B, substitute 35 for A in the equation below
A+B=280
35+B=280
B= 280-35
B= 245
Thus, the chef will be needing 35ml of the first brand and 245ml of the second brand.