My son with this question becuz even i don't know it

Asequence is defined recursively using the formula f(n + 1) =f(n) - 5. which sequence could be

Which of the following graphs could represent a cubic function?

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle? by using compass take the measures of angle and draw the same arc according to it.