16 is the answer just add
Answer:
The number of machines to complete job in 2 hours is 6.
Step-by-step explanation:
Using the relation of the rate of each one machine and knowing that adding up both rates.

Rate R =
'x' is the job
Rate S =
'x' is the job
So, using the equation of rates

Rate total is going to be a job in 2 hours so = 
<em>adding up</em>
<em>factoring the x</em>
<em>simplifying</em>
x= 
x= 6
Answer:
answer is 90 for first term
Step-by-step explanation:
Let the terms be
First term x
We 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 =4/5
s∞=x/1−r
450=x/1−4/5
450=x/1/5
450=5x
x=90
this is the first term x1 = 90
we 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