Answer:
150 mL
Step-by-step explanation:
Let x represent the quantity of 75% solution needed. The total amount of alcohol in the 60% mixture will be ...
75%·x + 10%·45 = 60%·(x+45) . . . . . there will be x+45 mL of solution in the end
0.15x = 22.5 . . . . . . . . . . . . . . . . . . . . simplify, subtract .60x+4.5
22.5/0.15 = x = 150 . . . . . . . . . . . . . . mL of 75% solution needed
You will need 150 mL of the 75% solution.
Answer and workings in the attachment below.
what does the ^ mean.
i will answer in the comments
If you would like to know the dimensions of the garden, you can calculate this using the following steps:
length ... (2 * x - 4) feet
width ... x feet
area ... 170 ft^2
area = length * width
170 = (2 * x - 4) * x
170 = 2 * x * x - 4 * x
170 = 2 * x^2 - 4 * x
0 = 2 * x^2 - 4 * x - 170 /2
0 = x^2 - 2 * x - 85
1. x = 1 - sqrt(86) = -8.27
2. x = 1 + sqrt(86) = 10.27
length: 2 * x - 4 = 2 * 10.27 - 4 = 16.54 feet
width: x = 10.27 feet
The dimensions of the garden are 16.54 feet and 10.27 feet.