Two solutions exist,
2(x - 1) = 8
2x - 2 = 8
2x = 10
x = 5
&
2(x + 1) = 8
2x + 2 = 8
2x = 6
x = 3
the two solutions are 5 and 3
It may be a special right triangle which would make the angles 45, 45, and 90
The complete question is
<span>Sarah rides her horse for 2 1/6 hrs with a constant speed of 6 km/hr and then for another 2 hours and 5 minutes with a constant speed of 12 km/hr what is her average speed for the total trip?</span>
we know that
speed=distance/time
1) Sarah rides her horse for 2 1/6 hrs with a constant speed of 6 km/hr
time=2 1/6 hrs----> 13/6 hrs
speed=6 km/h
distance=speed*time----> 6*(13/6)---> 13 km
2)for another 2 hours and 5 minutes with a constant speed of 12 km/hr
time=2hrs+5 minutes----> 2+(5/60)--> 125/60 hrs
speed=12 km/hrs
distance=speed*time----> 12*(125/60)---> 25 km
3) find the average speed for the total trip
total distance=13 km+25 km----> 38 km
total time=(13/6)+(125/60)----> (10*13+125)/60----> 4.25 hours
speed=38/4.25----> 8.94 km/hrs
the answer is
8.94 km/hrs
Option 4 is the answer.
50+30
=80
10(5+3)
= 10×8
=80
Hence, the correct option => 10(5+3)
Hope it helps!
