Answer:

Step-by-step explanation:
The series is an arithmetic series with first term (a1) -9 and common difference (d) 5. Then the general term (an) is ...
an = a1 +d(n-1) = -9 +5(n-1) = -14 +5n
The summation notation indicates the sum of "n" of these terms.
Answer:
Step-by-step explanation:
Drop an angle bisector from angle C until it intersects AB. Because of the symmetry of the triangles created, you will form two small right angle congruent triangles. Call the point of intersection with AB = D. In other words the bisector of <C is CD.
CB = AC Isosceles triangle
CD / CB = Sin(38.5)
CD=?
CB = 35
CD / 35 = Sin(38.5) Multiply both sides by 35
CD = 35 * sin(38.5)
CD = 21.79
BD/CB = Cos(38.5)
BD = CB* Cos(38.5)
BD = 35 * Cos (38.5)
BD = 27.39
Area = CD * BA/2
BA/2 = DB
Area = CD * BD
Area = 21.79 * 27.39
Area = 596.9
Answer:
The angle of elevation is approximately 
Step-by-step explanation:
Notice that the two pieces of information given: "400 ft away from a building", and building that is "850 ft tall", can be regarded as the two legs of a right angle triangle (see attached image).
Then the angle
that we are trying to find (the angle of elevation) can be found by using the arc-tangent function:

Value of x is 5. I remember doing this last year..
35a+45b=80
then we would do 99-80, and that gives us the value of c, 19