Answer:
how do you find the circumference of a circle??
C=2πr
C=2πr
3x + 2y = 39
5x - y = 13
Multiplying the last by two:
10x - 2y = 26
Adding to the first
13x = 65
x = 5
y = 5x-13 =25-13=12
Check:
3(5)+2(12)=39 good
5(5)-12=13 good
Answer: x=5, y=12
Answer:
Usual, because the result is between the minimum and maximum usual values.
Step-by-step explanation:
To identify if the value is usual or unusual we're going to use the Range rule of thumbs which states that most values should lie within 2 standard deviations of the mean. If the value lies outside those limits, we can tell that it's an unusual value.
Therefore:
Maximum usual value: μ + 2σ
Minimum usual value: μ - 2σ
In this case:
μ = 153.1
σ = 18.2
Therefore:
Maximum usual value: 189.5
Minimum usual value: 116.7
Therefore, the value of 187 lies within the limits. Therefore, the correct option is D. Usual, because the result is between the minimum and maximum usual values.
Answer:
Precambrian period
Step-by-step explanation:
Since the Great oxidation period = 2.4 Billion years ago era = Precambrian period.
Micro-fossils attributed to cyanobacteria are abundant during the Proterozoic that came later 2,5 billion years ago and ended 540 million years ago,
