[Probability / Statistics) Twenty families were surveyed. How many have boys only?
2 answers:
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Answer:
<h2><em>29.4 length and 21.4 width.</em></h2>Step-by-step explanation:
To fin the dimensions of the pool we need to use the total area of the pool plus the concrete walkway. Lets say that <em>W </em>is the width and <em>L </em>the length. We know that, the walkway has 3 ft wide, this means that the width and length are increased by 6ft (3ft on each side). So, the total area can be expressed like this: .
In addition, we know that the total area is 970 and the length is 8 ft longer than the width (). So:
With this quadratic equation we're gonna have to solution, the most reasonable is part of the answer. So, solving the equation we have as solutions: and
Therefore, the width is 21.4 ft, because the negative number cannot represent distances.
Using the relation between length and width:
<em>Therefore, the dimensions of the pool are 29.4 length and 21.4 width.</em>
Answer:
Step-by-step explanation:
1). 10 =
10(7 + x) = 1 + 7x
70 + 10x = 7x + 1
10x - 7x = 1 - 70
3x = -69
x = -23
2). 0.2 =
0.2(12 + x) = 6 + 2x
2.4 + 0.2x = 6 + 2x
2.4 - 6 = 2x - 0.2x
1.8x = -3.6
x = -2
3). 0.8 =
0.8(x + 0.5) = x
0.8x + 0.4 = x
x - 0.8x = 0.4
0.2x = 0.4
x = 2
4). 3.5 =
3.5(0.5 - x) = 4 + 2x
1.75 - 3.5x = 4 + 2x
-3.5x - 2x = 4 - 1.75
-5.5x = 2.25
x = -
x = -