U5 = a + 4d = 5
U7 = a + 6d = 3
Subtracting the first equation from the second gives
2d = -2 therefore d = -1
and then a + 4d = 5 implies that a = 9.
So Sn = n/2*{2a + (n-1)*d}
thus S10 = 10/2*{18 + 9*(-1)}
= 5*{9} = 45
This question is impossible to answer without knowing the difference between successive terms of the progression.
Any number you like. You need two terms to uniquely identify an arithmetic progression.
It is not possible to answer this question without information on whether the terms are of an arithmetic or geometric (or other) progression, and what the starting term is.
-4 is the first negative term. The progression is 24,20,16,12,8,4,0,-4,...
It is an Arithmetic Progression with a constant difference of 11 and first term 15.
This question is impossible to answer without knowing the difference between successive terms of the progression.
2
Any number you like. You need two terms to uniquely identify an arithmetic progression.
It is not possible to answer this question without information on whether the terms are of an arithmetic or geometric (or other) progression, and what the starting term is.
For an Arithmetic Progression, Sum = 15[a + 7d].{a = first term and d = common difference} For a Geometric Progression, Sum = a[1-r^15]/(r-1).{r = common ratio }.
-4 is the first negative term. The progression is 24,20,16,12,8,4,0,-4,...
85 (=17*5). The middle term is 5. There are 8 terms bigger than 5 and 8 smaller. The term smaller than 5 and next to it is 5 - r The term bigger than 5 and next to it is 5 + r So these two average 5. Similarly, the next pair outwards average 5; and so on. So the sum of the progression is equivalent to the sum of 8 pairs of numbers whose average is 5 and the middle term which is 5 ie 17 lots of 5.
We need help with answering this question.
It is an Arithmetic Progression with a constant difference of 11 and first term 15.
AP - Arithmetic ProgressionGP - Geometric ProgressionAP:An AP series is an arithmetic progression, a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 3, 5, 7, 9, 11, 13, … is an arithmetic progression with common difference 2. If the initial term of an arithmetic progression is and the common difference of successive members is d, then the nth term of the sequence is given by:and in generalA finite portion of an arithmetic progression is called a finite arithmetic progression and sometimes just called an arithmetic progression.The behavior of the arithmetic progression depends on the common difference d. If the common difference is:Positive, the members (terms) will grow towards positive infinity.Negative, the members (terms) will grow towards negative infinity.The sum of the members of a finite arithmetic progression is called an arithmetic series.Expressing the arithmetic series in two different ways:Adding both sides of the two equations, all terms involving d cancel:Dividing both sides by 2 produces a common form of the equation:An alternate form results from re-inserting the substitution: :In 499 AD Aryabhata, a prominent mathematician-astronomer from the classical age of Indian mathematics and Indian astronomy, gave this method in the Aryabhatiya (section 2.18) .[1]So, for example, the sum of the terms of the arithmetic progression given by an = 3 + (n-1)(5) up to the 50th term isGP:A GP is a geometric progression, with a constant ratio between successive terms. For example, the series is geometric, because each successive term can be obtained by multiplying the previous term by 1 / 2.Geometric series are one of the simplest examples of infinite series with finite sums, although not all of them have this property. Historically, geometric series played an important role in the early development of calculus, and they continue to be central in the study of convergence of series. Geometric series are used throughout mathematics, and they have important applications in physics, engineering, biology, economics, computer science, queuing theory, and finance.
This is referred to as a geometric progression - as opposed to an arithmetic progression, where each new number is achieved via addition or subtraction.
Arithmetic : (First term)(last term)(act of terms)/2 Geometric : (first term)(total terms)+common ratio to the power of (1+2+...+(total terms-1))