It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
The appropriate descriptors of geometric sequences are ...
... B) Geometric sequences have a common ratio between terms.
... D) Geometric sequences are restricted to the domain of natural numbers.
_____
The sequences may increase, decrease, or alternate between increasing and decreasing.
If the first term is zero, then all terms are zero—not a very interesting sequence. Since division by zero is undefined, the common ration of such a sequence would be undefined.
There are some sequences that have a common difference between particular pairs of terms. However, a sequence that has the same difference between all adjacent pairs of terms is called an <em>arithmetic sequence</em>, not a geometric sequence.
Any sequence has terms numbered by the counting numbers: term 1, term 2, term 3, and so on. Hence the domain is those natural numbers. The relation describing a geometric sequence is an exponential relation. It can be evaluated for values of the independent variable that are not natural numbers, but now we're talking exponential function, not geometric sequence.
I know this is not an answer but if your having trouble with this there is a website called Desmos all you do is type in the equation for the graph and it gives you the answer
??? Im lost in this question, could you be more specific?