The sum of an infinite geometric series is 450, while the common ratio of the series is 4/ 5 . What is the first term of the series? A) 22 1 2 B) 45 C) 90 D) 180

Accepted Solution

Answer:answer is 90 for first term Step-by-step explanation:Let the terms be  First term xWe will use the formula s∞=x/1−r to find the sum of an infinite geometric series, where −1<r<1.  We know the sum and the common ratio, so we'll be solving for x where r =4/5s∞=x/1−r450=x/1−4/5450=x/1/5450=5xx=90this is the first term x1 = 90we know that common ratio is 4/5, so multiplying the first term by factor 4/5 to get the second term   90 x 4/5=   72 second term