The answer is A. 42
Solution:
Let x= ones digit, y=tens digit
1st condition (original number) : 7(x+y)=10y + x
2nd condition (new number by reversing the digits): 18+x+y=10x+y
simplifying:
1st condition: 6x=3y
2nd condition: x=2
substituting x=2 to 6x=3y
<span>y=4</span>
Answer:
<em>A=3 and B=6</em>
Step-by-step explanation:
<u>Increasing and Decreasing Intervals of Functions</u>
Given f(x) as a real function and f'(x) its first derivative.
If f'(a)>0 the function is increasing in x=a
If f'(a)<0 the function is decreasing in x=a
If f'(a)=0 the function has a critical point in x=a
As we can see, the critical points may define open intervals where the function has different behaviors.
We have

Computing the first derivative:

We find the critical points equating f'(x) to zero

Simplifying by -6

We get the critical points

They define the following intervals

Thus A=3 and B=6
Look at the graph, which y values can the graph hit?
Anything above zero would be the right answer, since there is an asymptote at
.
So the range would be 
Hope this helps.
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