Answer:
The first term should be positive
She did not distribute the -4 properly
She added to negative -4 instead of multiplying
Step-by-step explanation:
In order to tell where she is wrong we should solve the question our selves. we are going to get the following......
So now we see that the three things she did wrong are.
The first term should be positive
She did not distribute the -4 properly
She added to negative -4 instead of multiplying
Hope this helps :)
Answer:
3.08 km/h.
Step-by-step explanation:
We know that,
Ali traveled at a speed of s km/h for 2.5 hours.
Let d be the distance and t be the time.
...(1)
On his return journey, he increased his speed by 4 km/h and saved 15 minutes. So, distance is d and times is t-15.
...(2)
From (1) and (2), we get
Put t=40 in (1).
So, t=40 and d=100.
Now,
Total distance = d + d = 100 + 100 = 200
Total time = t + t - 15 = 40 + 40 - 15 = 65
So, the average speed is
Therefore, the average speed is 3.08 km/h.