1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Finger [1]
3 years ago
9

In a certain sequence of numbers, each term after the first is found by doubling and then adding $3$ to the previous term. If th

e seventh term of the sequence is $125$, what is the first term?
Mathematics
1 answer:
Rufina [12.5K]3 years ago
5 0
We know that
an=[a(n-1)]*2+3
if a7=125 
a) Find a1

step 1
find a6
a7=a6*2+3--------> a6=(a7-3)/2-----> a6=(125-3)/2----> a6=61

step 2
find a5
a6=a5*2+3--------> a5=(a6-3)/2-----> a5=(61-3)/2----> a5=29

step 3
find a4
a5=a4*2+3--------> a4=(a5-3)/2-----> a4=(29-3)/2----> a4=13

step 4
find a3
a4=a3*2+3--------> a3=(a4-3)/2-----> a3=(13-3)/2----> a3=5

step 5
find a2
a3=a2*2+3--------> a2=(a3-3)/2-----> a2=(5-3)/2----> a2=1

step 6
find a1
a2=a1*2+3--------> a1=(a2-3)/2-----> a1=(1-3)/2----> a1=-1

the answer is
a1=-1




You might be interested in
I HAVE 10 MIN PLS HELP FIND THE VOLUME
egoroff_w [7]

Answer:

900

Step-by-step explanation:

The figure is a triangular prism

The equation would be V = A * H / 3

V being the volume

A being the area of the pyramids base

H being the height front he base to the top  (20)

Base area is 135 (A)

135 * 20 = 2700

2700 divided by 3 = 900

900 is your answer

8 0
2 years ago
Which of the following is true about a nonlinear function?
Mila [183]
It is not straight and does not always pass through 0,0
so A, C, and D are incorrect.

Look up nonlinear function, and it shows a curved line.

The answer is B. It can be curved.
8 0
2 years ago
Read 2 more answers
Find the missing side of the angle.<br> Need help, thank you!!
Alex787 [66]

Answer:

sqrt239

Step-by-step explanation:

Using the pythagoream thereom, we know that a^2+b^2=c^2.

so x^2+17=256

That makes x the square root of 239.

4 0
2 years ago
A furniture store is having a weekend sale and is offering a 20% discount on patio chairs and tables. The sales tax on furniture
dalvyx [7]
First, we subtract 20% of the amount from x, so the initial cost of the furniture should be 80% of x or 0.80x. Then, due to the sales taxs, this amount should be added with 6.25% of itself. Such that,
                                   A = 0.80x + 0.0625(0.80x)
                                       = 0.85x
4 0
3 years ago
Read 2 more answers
Hi, can somoene please check why my solution and explain why I get the wrong answer.
trapecia [35]

Answer:

a_n=(1-n)2^n+3^n

Step-by-step explanation:

You are correct down to the part where you add the partial results:

a_n=a_n^h+a_n^p=A3^n+B2^n-n2^n\\\text{Using the given starter values, we can find A, B:}\\a_0=2=A\\a_1=7=3A+2B+2\\\text{has solution A=1, B=1, so ...}\\\\a_n=3^n+2^n-n2^n

4 0
3 years ago
Other questions:
  • Solve this equation for<br> a. A ÷ 2 = 4<br> a. 8<br> B. 2<br> C. 6<br> D. 4
    13·2 answers
  • How do i work this problem out
    8·1 answer
  • A house cost $150,000. If a loan is taken out for 15 years at 3.5%, what is the interest on the loan?
    10·1 answer
  • Heeeeeeeeeeeeeeeeeeeeeellllllllllllllllllllllllllllllllllllllllllppppppppppppppppppppp
    5·1 answer
  • Jade solved the following equation:
    11·1 answer
  • A company makes plastic beach balls with a radius of 2 inches. How many square inches of plastic does the company
    12·2 answers
  • -2 &lt; 3x -5 ≤ 4 pls help
    11·2 answers
  • PLSSS HELPpPP URGENT
    5·2 answers
  • Adam biked 6 3/4 miles to work and then 3 2/5 miles to the store. How many miles had he biked that day when he arrived at the st
    8·1 answer
  • Which of the following is an increasing exponential function whose y-intercept is 50?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!