First we must look at the sequence 15,9,3,-3...
You can see that the value is decreasing by 6 every term. Because the rate is drawing at a constant rate the sequence must be linear, meaning that the slope is -6.
If we look at the general function of a line in slope intercept form:

where m is the slope and b is the y intercept. The trick to find the y intercept is to go backwards, in other words what was the previous term? 15+6=21. Therefore, m=-6 and b=21 and thus,

Since we want to know the value of y even x=20 we obtain:
Answer:
°
Step-by-step explanation:
A secant is a line that intersects a circle in two places. The secants interior angle theorem states that when two secants intersect a circle inside a circle, the measure of any one of the angles formed is equal to half of the sum of the two intersecting arcs. Therefore, one can apply this theorem here:

Simplify,



This is how it looks on a graph.
Answer:8.5
Step-by-step explanation:
Pythagorean Theorem
A
a^2 + b^2 = c^2
3^2 + 8^2 = c^2
9 + 64 = c^2
73 = c^2
C= Sqrt (73)
C = 8.5