There are 10 girls in the class. You want to multiply (3/5)x25, once product is found, you subtract it from 25, the product is 15, so 25-15=10girls
Straight line angled up to the right intersecting the y axis at y=-7/3
The sum of the first n terms of sequence 85 +85(.9) +85(.9)² + ... would be 348.08.
<h3>What is the sum of terms of a geometric sequence?</h3>
Let's suppose its initial term is a , multiplication factor is r and let it has total n terms,
then, its sum is given as:
![S_n = \dfra](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cdfra)
![\dfrac{a(r^n-1)}{r-1}](https://tex.z-dn.net/?f=%5Cdfrac%7Ba%28r%5En-1%29%7D%7Br-1%7D)
(sum till nth term)
Given geometric sequence;
85 +85(.9) +85(.9)² + ...
a = 85
r = 0.9
its sum is given as:
![S_n = \dfra](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cdfra)
![\dfrac{a(r^n-1)}{r-1}](https://tex.z-dn.net/?f=%5Cdfrac%7Ba%28r%5En-1%29%7D%7Br-1%7D)
![S_n = \dfrac{85(0.9^5-1)}{0.9-1}\\\\S_n = \dfrac{85(0.5904-1)}{-0.1}\\\\\\S_n = \dfrac{85(-0.4095)}{-0.1}\\\\S_n = 348.08](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cdfrac%7B85%280.9%5E5-1%29%7D%7B0.9-1%7D%5C%5C%5C%5CS_n%20%3D%20%5Cdfrac%7B85%280.5904-1%29%7D%7B-0.1%7D%5C%5C%5C%5C%5C%5CS_n%20%3D%20%5Cdfrac%7B85%28-0.4095%29%7D%7B-0.1%7D%5C%5C%5C%5CS_n%20%3D%20348.08)
Thus,
The sum of the first n terms of sequence 85 +85(.9) +85(.9)² + ... would be 348.08.
Learn more about geometric sequence here:
brainly.com/question/2735005
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Answer:
X=45
Step-by-step explanation:
90 - 45 = 45