Geometric sequence

In the geometric sequence is a4 = 20 a9 = -160. Calculate the first member a1 and quotient q.

Result

q =  -1.516
a1 =  -5.743

Solution:     Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...): Be the first to comment! To solve this verbal math problem are needed these knowledge from mathematics:

Do you have a system of equations and looking for calculator system of linear equations?

Next similar math problems:

1. Geometric sequence 3 In geometric sequence is a8 = 312500; a11= 39062500; sn=1953124. Calculate the first item a1, quotient q and n - number of members by their sum s_n.
2. Geometric sequence 4 It is given geometric sequence a3 = 7 and a12 = 3. Calculate s23 (= sum of the first 23 members of the sequence).
3. Tenth member Calculate the tenth member of geometric sequence when given: a1=1/2 and q=2
4. Sequence Calculate what member of the sequence specified by ? has value 86.
5. Geometric progression 2 There is geometric sequence with a1=5.7 and quotient q=-2.5. Calculate a17.
6. Five members Write first 5 members geometric sequence and determine whether it is increasing or decreasing: a1 = 3 q = -2
7. Six terms Find the first six terms of the sequence a1 = -3, an = 2 * an-1
8. GP - 8 items Determine the first eight members of a geometric progression if a9=512, q=2
9. Geometric progression 4 8,4√2,4,2√2
10. Computer The computer was purchased 10000,-. Each year, the price of a computer depreciates always the same percentage of the previous year. After four years, the value of the computer is reduced to 1300,- How many percent was depreciated price of the computer each
11. Calculation How much is sum of square root of six and the square root of 225?
12. Power Number ?. Find the value of x.
13. Linsys2 Solve two equations with two unknowns: 400x+120y=147.2 350x+200y=144
14. Theorem prove We want to prove the sentence: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
15. Powers 3 2 to the power of n divided by 4 to the power of -3 equal 4. What is the vaule of n?
16. Log if ?, what is b?
17. The city 3 The city has 22,000 residents. How long it is expected to have 25,000 residents if the average annual population growth is 1.4%?