Use elimination
3x + 4y = -2
2x - 4y = -8
Add both equations
5x = -10, x = -2
3(-2) + 4y = -2
-6 + 4y = -2
4y = 4, y = 1
Solution: x = -2, y = 1
From the given, we have 232 90Th. Thorium has 90 protons in its nucleus, the number of neutrons is calculated by subtracting 90 from 232 which gives an answer of 142. Then, for the second given 228 88Ra, Radium has 88 protons and the number of its neutrons is calculated by subtracting 88 from 228 which is equal to 140.
The final equation that would give us the proper nuclear decay reaction,
232 90Th --> 228 88Ra + 4 2a
where 4 2a is an alpha particle.
In case A, as the error would be a difference of 1, the assumption could be mantained, but in case B the difference will be bigger, showing that the ratio is not 3:1 but 4:1.
<h3><u>Ratios</u></h3>
Given that a preliminary study was carried out to test the hypothesis that the ratio of white to dark herons on the island was 3:1, but A) a small census found 16 white morphs and 4 dark, to determine if the assumption of a 3 :1 ratio could be rejected, and B) to determine the same question if the census were larger with 160 white morphs and 40 dark, the following calculations must be made:
A)
- 3 + 1 = 4
- 16 + 4 = 20
- 4 = 20
- 3 = X
- 60 / 4 = X
- 15 = X
- Therefore, as the error would be a difference of 1, the assumption could be mantained.
B)
- 3 + 1 = 4
- 160 + 40 = 200
- 150 = 3:1
- In this case, the difference will be bigger, showing that the ratio is not 3:1 but 4:1.
Learn more about ratios in brainly.com/question/1504221
The formula of a perimeter of a rectangle:
We have:
Substitute
<h3>Answer: Length = 35 in, Width = 25 in.</h3>
