Answer:A, B and D
Step-by-step explanation:
A linear relationship is one in which when the variables are plotted, the graph would be a straight line. In a linear relationship, the highest power of the variables is 1. We would compare each of the given relations.
A) Double x and subtract five to get y. This is expressed as
2x - 5. It is a linear relationship.
B) Multiply x and y to get 20. This is expressed as
xy = 20. It is a linear relationship.
C) Multiply x times itself and add five to get y. This is expressed as
x^2 = y. It is not a linear relationship. The highest power of the variables is 2
D)Divide 40 by x to get y. This is expressed as
40/x = y. It is a linear relationship.
The speed of the current is 25 kilometers per hour.
<h3>What is the speed of the current?</h3>
According to the statement, Naira traveled first with the current and later against the current, both in the same amount of time. We assume that both the speed of the current and the speed of the vehicle are constant. Hence, the travel time can be expanded to the following expression:
s₁ / (v + v') = s₂ / (v - v')
Where:
- s₁ - Distance traveled with the current, in kilometers.
- s₂ - Distance traveled against the current, in kilometers.
- v - Speed of the current, in kilometers per hour.
- v' - Speed of the vehicle relative to the current, in kilometers per hour.
If we know that s₁ = 4.5 km, s₂ = 3 km, v' = 5 km /h, then the speed of the current is:
4.5 / (v + 5) = 3 / (v - 5)
4.5 · (v - 5) = 3 · (v + 5)
4.5 · v - 22.5 = 3 · v + 15
1.5 · v = 37.5
v = 25
The speed of the current is 25 kilometers per hour.
To learn more on relative speeds: brainly.com/question/14362959
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51 and the other one us 15 your welcome
We will use the Cosine law:
c² = a² + b² - 2 a b cos C
In this case:
15² = 10² + 7² - 2 · 10 · 7 cos K
225 = 100 + 49 - 140 cos K
76 = - 140 cos K
cos K = - 76 / 140
cos K = - 0.5428
∠ K= cos ^(-1) ( -0.5428 ) = 122.88° ( the largest angle )
49 = 100 + 225 - 2 · 10 · 15 cos J
- 276 = -300 cos J
cos J = 0.92
∠J = cos ^(-1) 0.92 = 23.08° ( the smallest angle )
122.8° - 23.08° = 99.8°
Answer: D )