Question 1192189
Here's how to solve this problem:

**1. Set up the variables:**

* Let *u* represent the number of empty seats for United Continental.
* Let *a* represent the number of empty seats for American.
* Let *s* represent the number of empty seats for Southwest.

**2. Set up the equations:**

* **Equation 1 (Total empty seats):** u + a + s = 235
* **Equation 2 (United Continental empty seats):** u = 3a
* **Equation 3 (Total cost of empty seats):** 0.149 * 3000 * u + 0.146 * 3000 * a + 0.124 * 3000 * s = 99060

**3. Simplify Equation 3:**

447u + 438a + 372s = 99060

**4. Substitute Equation 2 into Equation 1 and Equation 3:**

* **New Equation 1:** 3a + a + s = 235  =>  4a + s = 235
* **New Equation 3:** 447(3a) + 438a + 372s = 99060  => 1341a + 438a + 372s = 99060  => 1779a + 372s = 99060

**5. Solve the system of two equations (New Equation 1 and New Equation 3):**

One way to do this is using substitution or elimination.  Let's use substitution:

* From New Equation 1: s = 235 - 4a

Substitute this into New Equation 3:

1779a + 372(235 - 4a) = 99060
1779a + 87420 - 1488a = 99060
291a = 11640
a = 40

Now substitute a = 40 back into the equation for s:

s = 235 - 4(40)
s = 235 - 160
s = 75

Finally, substitute a = 40 back into the equation for u:

u = 3(40)
u = 120

**Solution:**

* United Continental: 120 empty seats
* American: 40 empty seats
* Southwest: 75 empty seats