it wants you to make a table of the inputs and out puts, and what is the pattern that is happening. like is it a constant increase/decrease and things like that. i'll help you on the table...
x | y
1 | 5
2 | 4
3 | 3
4 | 2
(i am not sure what that 40 is at the end, but You get the point)
now all you have to do is identify the sequence or pattern you see here
3/4(x+21) = 10.5
0.75x+15.75 = 10.5
0.75x = -5.25
x = -7
Hope it helps : )
For this case we have that by definition, a direct variation is given by:

Where:
k: It is the constant of proportionality of the variables.
On the other hand, we have that the inverse variation is given by:

Where:
k: It is the constant of proportionality of the variables.
In this way, the correct option is: 
ANswer:
Option A
Answer:
KM=41.6
Step-by-step explanation:

Cross Multiply and Solve for KM.

Answer:
320 pesos
Step-by-step explanation:
Un 20% de descuento en formato decimal es 0.20. La totalidad de la bicicleta es representada como 100% o 1 y nosotros queremos saber el precio despues del descuento que seria
100% - 20% = 80% o 0.80
Ahora simplemente multiplicamos este decimal por el valor original de la bicicleta para saber el precio descontado...
400 * 0.80 = 320 pesos