Part a), solve this system of equations:
x + y = 5
x - y = 2.25
2x = 7.25
x = 3.625
y = 1.375
part b), solve this system of equations:
x + y = 5
x = 3y
y = 1.25
x = 3.75
Answer:
97
Step-by-step explanation:
Given that:
Low = 43bpm
High = 115 bpm
Error = 3
α = 90%
To find the range estimate :
Standard destviation = (high - low) / 4
Standard deviation = (115 - 43) / 4
Standard deviation = 72/4 = 18
The sample size,(n) :
n = [(Zα/2 * sd)/E] ²
2 - tail = (Zα/2) = 1.645
[(Zα/2 * sd)/E] ² = [(1.645 * 18) / 3]² = (29.61/3)²
= 97.41
Sample size = 97
Answer:
The dimensions of the yard are W=20ft and L=40ft.
Step-by-step explanation:
Let be:
W: width of the yard.
L:length.
Now, we can write the equation of that relates length and width:
(Equation #1)
The area of the yard can be expressed as (using equation #1 into #2):
(Equation #2)
Since the Area of the yard is
, then equation #2 turns into:

Now, we rearrange this equation:

We can divide the equation by 5 :

We need to find the solution for this quadratic. Let's find the factors of 160 that multiplied yields -160 and added yields -12. Let's choose -20 and 8, since
and
. The equation factorised looks like this:

Therefore the possible solutions are W=20 and W=-8. We discard W=-8 since width must be a positive number. To find the length, we substitute the value of W in equation #1:

Therefore, the dimensions of the yard are W=20ft and L=40ft.
Answer:
7/20
Explanation:
In order to do this, you must first simplify all the equations to the simplest forms. Do this by simplifying 3/6 to 1/2. We know this because 3 is half of 6, therefore it would reduce down to 1/2. 7/10 is already simplified; we know this because 7 is a prime number and can’t do down any further
Now, multiply the two fractions buy multiplying the numerators and denominations together. In other words, 1 x 7 is 7 so your numerator is 7, and 2 x 10 is 20 so your denominator is 20.
Sorry that’s it’s sloppy i tried to write it on my phone. hope this part helps. i’ll try to do the bottom part now