The answer to the first question of the attached document is option 1. We obtain the answer subtracting the term n from the series with the term n-1.For example:
-3 - (- 5) = 2
-1 - (- 3) = 2
1 - (- 1) = 2
So you can see that the common difference is the 2.
The answer to the second question is option 3:
y = | x + 7 |
We can confirm it by substituting values in the equation.
For example:
if we do y = 0 then x = -7
if we do x = 0 then y = 7.
As corresponds in the graph shown.
Remember also that as a general rule yes to the equationy = | x | whose vertex is in the point (0,0) we add a positive real number "a" of form y = | x + a | then the graph of y = | x | will move "to" units in the negative direction of x.
The answer to the third question is option 4.
The quotient of x and "and" is constant.
k = y / x
Rewriting:
y = kx
You can see that it corresponds to the equation of a line that passes through the origin, this means that and is proportional to x and both vary directly
An = a1 + (n-1)d
an = 27 + (n-1)(-6)
