5(x + y) - 3(x - y)
5x + 5y - 3x + 3y
5x - 3x + 5y + 3y
2x + 8y
5(x + y) - 3(x - y) = 2x + 8y
Depending on if you're solving for X or Y:
X less than or equal to 4y/3 -5
Y greater than or equal to 3x/4+15/4
Answer:
3729.5521 exact 3729.55 rounded
Step-by-step explanation:
Because x,y,z form a geometric sequence, therefore the common ratio is
r = y/x = z/y
That is,
y² = xz (1)
We are given:
x + y + z = 18
Therefore
x + z = 18 - y (2)
Also,
x² + y² + z² = 612
Therefore, from (1), obtain
x² + z² + xz = 612
(x + z)² - xz = 612
From (1) and (2), obtain
(18 - y)² - y² = 612
324 - 36y + y² - y² = 612
-36y = 288
y = -8
Answer: y = -8
