Register

If x+2y=3 and xy=2 show that x³+8y³+9=0​

If x+2y=3 and xy=2 show that x³+8y³+9=0​
asked 23.4k views
13 votes
If x+2y=3 and xy=2 show that x³+8y³+9=0​

asked
User Sorcy
by
8.0k points

1 Answer

8 votes

Explanation:

Given

  • x + 2y = 3 and xy = 2
  • show that x³ + 8y³ + 9 = 0​

Solution in steps:

  • (x + 2y)³ = 3³
  • x³ + 3x²(2y) + 3x(2y)² + (2y)³ = 27
  • x³ + 6x(xy) + 12y(xy) + 8y³ = 27
  • x³ + 8y³ + 6(x + 2y)xy = 27 ⇒ Substitute values
  • x³ + 8y³ + 6*3*2 = 27
  • x³ + 8y³ + 36 - 27 = 0
  • x³ + 8y³ + 9 = 0

Done

answered
User Harish Bagora
by
7.8k points
← Prev Question Next Question →

Related questions

User Mithson
asked Jan 20, 2024 63.5k views
If x - y = 3(z-y), then (x³ + 8y³-27z³)÷(xyz) = ​
Mithson asked Jan 20, 2024
by Mithson
7.7k points
1 answer
0 votes
63.5k views
Ask a Question
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.

Categories

Other Questions

How do you can you solve this problem 37 + y = 87; y =
How do you estimate of 4 5/8 X 1/3
A bathtub is being filled with water. After 3 minutes 4/5 of the tub is full. Assuming the rate is constant, how much longer will it take to fill the tub?
Link Copied!