Which expression is equivalent to 18 - 7? Apex
1 answer:
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Answer: The answer is (D) Reflection across the line y = -x.
Step-by-step explanation: In figure given in the question, we can see two triangles, ΔABC and ΔA'B'C' where the second triangle is the result of transformation from the first one.
(A) If we rotate ΔABC 180° counterclockwise about the origin, then the image will coincide with ΔA'B'C'. So, this transformation can take place here.
(B) If we reflect ΔABC across the origin, then also the image will coincide with ΔA'B'C' and so this transformation can also take place.
(C) If we rotate ΔABC through 180° clockwise about the origin, the we will see the image will be same as ΔA'B'C'. Hence, this transformation can also take place.
(D) Finally, if we reflect ΔABC across the line y = -x, the the image formed will be different from ΔA'B'C', in fact, it is ΔA'D'E', as shown in the attached figure. So, this transformation can not take place here.
Thus, the correct option is (D).
Answer:
5 hours
Step-by-step explanation:
given :
Distance between the cities = 540 miles
Speed of motorcycle =48 mph
TO CALCULATE THE TIME TAKEN BY MOTORCYCLE TO COVER THE TOTAL DISTANCE WE USE THE FORMULA :
By putting given values in the formula we get :
= 11.25 hours
Now, We are given that for a car to cover the same distance it takes 2.25 hours less than the time taken by motorcycle
⇒ 11.25 hours - 2.25 hours
⇒ 9 hours
Thus , Time taken by car to cover the same distance is 9 hours .
Now to calculate speed of car by using formula:
= 60 mph
Let t be the time taken to meet if they start moving towards each other.
So distance covered by motorcycle in t hours is
speed\times time
= 48t miles
Distance covered by car in t hours is
speed\times time
= 60t miles
⇒ 60t + 48t =540
⇒ 108t = 540
⇒ t= 5 hours
Therefore, time taken to meet if they start moving towards each other is 5 hours.
