The days she has recorded: 11 + 10 + 7 + 6 + 3 + 2 = 39
The mode distance (most often): 5 km
Median distance: 6.64 km ~= 6.5 km ~= 7 km by rounding upwards, so 3rd
Cumulative frequency: 11; 21; 28; 34; 37; 39
The like terms in 10a+4b+3a-15b consist of a and b. First, we have to combine like terms.
(10a+3a) + (4b-15b)
solve a and b
13a - 11b. Thus, the like terms in your original expression are 13a and -11b :)
We have to find the average rate of meters per second (also known as average speed).
We can calculate it as the quotient between the distance and the time:

Answer: the average rate is approximately 7.58 m/s.
The tots of two numbers, or you know the communitive property