Quality Learning Support For Better Outcomes
First time here? Checkout the FAQs!
MathsGee is Zero-Rated (You do not need data to access) on: Telkom |Dimension Data | Rain | MWEB

0 like 0 dislike

The sequence $4 ; x ; y ; 18$ is such that $ 4 ; x ; y $ form an arithmetic sequence and $x,y$ and 18 form a geometric sequence

  1. Using the common difference of the arithmetic sequence, determine $y$ in terms of $x$
  2. Using the common ratio of the geometric sequence, determine $y$ in terms of $x$
  3. Hence, or otherwise, calculate the value(s) of $x$ and $y$


in Mathematics by Diamond (81,060 points) | 244 views

1 Answer

0 like 0 dislike
1. x-4=y-x


2. y/x = 18/y

       y^2 = 18x

          y= sqroot(18x)

3. y=2x-4


          18x= (2x-4)^2

         4x^2 -34x+16=0

      2x^2 -17x+8=0


          x= 1/2 or 8

then y= 2(1/2)-4= -3  or y= 2(8)-4=12
by Diamond (44,170 points)

Related questions

0 like 0 dislike
1 answer
1 like 0 dislike
1 answer
1 like 0 dislike
1 answer

Join the MathsGee Answer Hub community and get study support for success - MathsGee Answer Hub provides answers to subject-specific educational questions for improved outcomes.

On MathsGee Answers, you can:

  1. Ask questions
  2. Answer questions
  3. Comment on Answers
  4. Vote on Questions and Answers
  5. Donate to your favourite users
  6. Create/Take Live Video Lessons

Posting on MathsGee

  1. Remember the human
  2. Behave like you would in real life
  3. Look for the original source of content
  4. Search for duplicates before posting
  5. Read the community's rules
MathsGee Tools

Math Worksheet Generator

Math Algebra Solver

Trigonometry Simulations

Vectors Simulations

Matrix Arithmetic Simulations

Matrix Transformations Simulations

Quadratic Equations Simulations

Probability & Statistics Simulations

PHET Simulations

Visual Statistics

MathsGee ZOOM | eBook