Answer:
z = -12
Step-by-step explanation:
The given system of equations is:
xy/(x + y) = 1 ...........................(1)
xz/(x + z) = 2...........................(2)
yz/(y + z) = 3...........................(3)
From (1): x + y = xy
=> y = xy - x
y = x(y - 1)
x = y/(y - 1).......................................(4)
From (2): 2(x + z) = xz
=> 2x + 2z = xz
2x = xz - 2z
2x = z(x - 2)
z = 2x/(x - 2) ....................................(5)
From (3): 3(y + z) = yz
=> 3y + 3z = yz
3y = yz - 3z
3y = z(y - 3)
z = 3y/(y - 3)....................................(6)
Comparing (5) and (6)
2x/(x - 2) = 3y/(y - 3)
2x(y - 3) = 3y(x - 2)
2xy - 6x = 3xy - 6y
6(y - x) = xy .................................(7)
But from (1): xy = x + y
Using this in (7), we have
6(y - x) = x + y
6y - y - 6x - x = 0
5y - 7x = 0
5y = 7x
x = 5y/7................................................(8)
Using this in (4)
5y/7 = y/(y - 1)
1/(y - 1) = 5/7
(y - 1) = 7/5
y = 1 + 7/5
y = 12/5..........................................(9)
Using this in (8)
x = 5(12/5)/7 = 12/7 .......................(10)
Using (10) in (5)
z = 2x/(x - 2)
z = 2(12/7) ÷ (12/7 - 2)
= 24/7 ÷ -2/7
= 24/7 × (-7/2)
= -24/2 = -12
z = -12.
(x+1)(x+14) This would be the answer
Answer:
254 4/7 or 254.34 ft² (it depends on which method you use.)
Step-by-step explanation:
To find the area of a circle, the formula is πr².
I'll use both 22/7 and 3.14 as pi, so I'll end up with two different answers. Just choose the more reliable one.
22/7 version:
22/7 * 9^2
22/7 * 81/1
1782/7
254 4/7 ft²
3.14 version:
3.14 * 9^2
3.14 * 81
314 - (3.14 * 19)
314 - 62.8 + 3.14
251.2 + 3.14
254.34 ft²
As I said, I ended up with two different answers. You also had said not to round my answer, so the 22/7 version has a mixed number.
Value of the boat after 9 years= 12050*(1-0.12)^9
=$3814(correct to nearest integer)
Answer:
Carl and Alex are wearing hats.
Step-by-step explanation:
If Bob doesn't isn't wearing a hat, then Carl is, so Carl clearly is wearing a hat.
Now let's look at Alex. If he wasn't wearing a hat, then Bob would be wearing one. (If Alex doesn't wear a hat, then Bob wears
a hat). The logical conclusion is that Alex must be wearing a hat as well.
