Could someone verify my answers in the following problems?

1. An aircraft can fly 912 miles with the wind in three hours, while it takes the same aircraft four hours to fly the same distance against the wind. Find the speed of the aircraft in still air, and the speed of the wind.

**A= aircraft = 266 MPH** and

**W=wind= 38 MPH** **<--- Correct**
2. Without graphing, determine the number of solutions this system has:

3x+2y=3

-12x-8y= -5

**No solution for this system** **<--- Correct**
3. Solve this system by graphing:

7x-2y=24

x=y=-3

Put into slope-intercept form:

y=7/2x-12

y= -x-3

**My lines shape an X and they intercept at (2, -5)** **<--- Correct**
4. Solve this system without graphing:

2/5x+3/5y= -4

1/3x+2y= -28/3

**(-4, -4)** **<--- Correct**
5. Solve this system (double elimination):

5x-2y=9

6x+7y=4

**(71/47, -34/47)** **<--- Correct**
6. Solve this system without graphing:

5(3y-1) = x+20

4(x+2)-18 = 2x-6(y-2)

**( -10, 1/3)****<--- Unfortunately wrong**