ANSWER
EXPLANATION
The sum of the first 
terms of a geometric sequence is given by;
Where , is the number of terms and 
is the first term.
When 
, we have 
, we get;
for these you need to rearrange the equations and do substitutions.
#3 = if x+y=5 then you know x = 5-y
now substitute that equation for x in the 2nd one so x + 2y = 8 becomes
5-y + 2y = 8 2y - y becomes 1y which becomes y then subtract 5 from each side to get y =3
now replace y with 3 in the first equation x = 5-3 so x = 2
so (2,3) is the answer
same type of work for #4
2x-y=6 ,S0 y = 2X+6
so now you have 4x+2(2x+6)=-4
that becomes 4x +4x+12 = -4
8x+8 = 1, x =1
y = 2(1)-6 = -4
so answer is (1,-4)
The answer to your question is 10 seconds. I know this because:
distance divided by speed=time
let t=time
t=2*6(30/36)=10
t=10
So, it took Boris a total of 10 seconds to run up the out of service elevator.
Hope this helps!
Answer:
The answer is -(29+3a).
Step-by-step explanation:
=2(3-4a)+5(a-7)
= 6- 8a +5a -35
= 6-35-8a+5a
= -29-3a
= -(29+3a)
<em>Hope</em><em> </em><em>it helps</em><em>.</em><em>.</em>
Unit rate is a ratio between two different units with a denominator of one. When we divide a fraction's numerator by its denominator, the result is a value in decimal form. For example: 8/4 = 2 and 3/6 = 0.5. When we write numbers in decimal form, we can write them as a ratio with one as the denominator.
For example, we can write 2 as 2/1, and 0.5 as 0.5/1. However, since that approach can be a little clumsy, we usually drop the one. That said, it's important to remember the one is there, especially when working with unit rates.
For instance, 8 miles/4 hours = 2 miles/hour. Notice again that, while we did not include the 1, we did include the unit 'hour' Miles per hour is a familiar expression, as are unit rates such as:
interest/amount invested
revolutions/minute
salary/year
Conversationally, the word ''per'' indicates we are using a unit rate.
