For this case, the first thing we must do is define a variable.
We have then:
n: number of days.
We now write the explicit formula that represents the problem.
We have then:
an = 4n + 15
Where,
15: crunches the first day
4: increase the number 4 each day
Answer:
An explicit formula for the number of crunches Abbie will do on day n is:
an = 4n + 15
(8v + s)5 (multiply 5 into the parentheses)
(8v × 5) + (s × 5)
40v + 5s
To convert from rectangular coordinate (x, y) to polar coordinate (r, θ).
r is given by the square root of the sum of the squares of the rectangular coordinate.

and θ is given by the arctan of the ratio of y to x.

Example:
To convert rectangular coordinate (3, 4) to polar coordinate

Therefore, rectangular coordinate (3, 4) = polar coordinate (5, 53.13°)