Answer:
x=9
Step-by-step explanation:
(x+3)/2=6
Multiply each side by 2
2*(x+3)/2=6*2
x+3 = 12
Subtract 3 from each side
x+3-3 = 12-3
x = 9
There is a lot to go over here. Unfortunately it looks like you got a lot incorrect. I'll focus on two problems. Hopefully these examples below will help correct the other mistakes.
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Problem 7)
We have the starting value be 20 and the ending value be 11. Subtract the values: (end)-(start) = 11 - 20 = -9. The negative indicates we have a drop or decrease.
We'll focus on the positive version of this number, so 9. Divide this value over the starting amount 20 to get 9/20 = 0.45 = 45%
So going from 20 miles to 11 miles is a decrease of 45%
Answer to problem 7 is: 45%
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Problem 13)
An increase of 300% means we added 3 times the original amount onto the original amount.
We take 300% of 25 to get 3*25 = 75
Which is then added onto 25 to get 25+75 = 100
Answer to problem 13 is: 100
<u><em>Answer:</em></u>
Part a .............> x = 11
Part b .............> k = 57.2
Part c .............> y = 9.2
<u><em>Explanation:</em></u>
The three problems deal with inverse variation between two variables
An inverse variation relation between two variables means that when one of the variables increases, the other will decrease (and vice versa)
<u>Mathematically, an inverse variation relation is represented as follows:</u>
where x and y are the two variables and k is the constant of variation
<u><em>Now, let's check the givens:</em></u>
<u>Part a:</u>
We are given that y = 3 and k = 33
<u>Substitute in the original relation and solve for x as follows:</u>
<u>Part b:</u>
We are given that y = 11 and x = 5.2
<u>Substitute in the original relation and solve for k as follows:</u>
<u>Part c:</u>
We are given that x=7.8 and k=72
<u>Substitute in the original relation and solve for y as follows:</u>
to the nearest tenth
Hope this helps :)
Answer:
We have in general that when a function has a high value, its reciprocal has a high value and vice-versa. That is the correlation between the function. When the function goes close to zero, it all depends on the sign. If the graph approaches 0 from positive values (for example sinx for small positive x), then we get that the reciprocal function is approaching infinity, namely high values of y. If this happens with negative values, we get that the y-values of the function approach minus infinity, namely they have very low y values. 1/sinx has such a point around x=0; for positive x it has very high values and for negative x it has very low values. It is breaking down at x=0 and it is not continuous.
Now, regarding how to teach it. The visual way is easy; one has to just find a simulation that makes the emphasis as the x value changes and shows us also what happens if we have a coefficient 7sinx and 1/(7sinx). If they have a more verbal approach to learning, it would make sense to focus on the inverse relationship between a function and its reciprocal... and also put emphasis on the importance of the sign of the function when the function is near 0. Logical mathematical approach: try to make calculations for large values of x and small values of x, introduce the concept of a limit of a function (Where its values tend to) or a function being continuous (smooth).
