An = a1 * r^(n-1)
-405 = -5*3^(n-1)
3^(n-1) = 81
3^4 = 81 so n-1 = 3 and n = 4
Sn = S4 = -5 (1 - 3^4) / ( 1 - 3) = 400 / -2 = -200 Answer
Answer:
veinte
Step-by-step explanation:
Son veinte porque si alineas 10 + 10 así-
10
+ 10, solo agregas las que serán un dos. Luego sueltas el cero, que será 20.
Answer:
(x+4)^2 + (y-9)^2 = 25
Step-by-step explanation:
We can use the equation (x-h)^2 + (y-k)^2 = r^2
where (h,k) is the center and r is the radius
The center is at (-4,9) and the diameter is 10 which means the radius is 10/2 or 5
(x- -4)^2 + (y-9)^2 = 5^2
(x+4)^2 + (y-9)^2 = 25
Answer:
x = 20°
y = 70°
Step-by-step explanation:
the angle adjacent to the 40° angle must be 140° because the two angles form a straight line (which contains 180°)
in the isosceles triangle with the 'x', that means the other two angles must be equal and are (180-140) ÷ 2, which equals 20°
to find 'y', consider the larger right triangle with angles of 90° and 20°; angle y must equal 180 - (90 + 20) = 70°
