please check my answers

1.Use Gaussian elimination to write the system of equations given below in row-echelon form.

2x+4y+z=-4
2x-4y+6z=13
4x-2y+z=6

answer:2x+4y+z=-4
8y-5z=-17
z=1

2.Find the solution to the system of equations given below.
x+y+z=2
-x+3y+2z=8
4x+y=4

answer: 0,4,-2

3.Find the solution to the system of equations given below.

-x+3y+z=4
4x-2y-5z=-7
2x+4y-3z=12
Answer:no solution

4.Write the form of the partial fraction decomposition of the rational expression.
2x-4/x^2-1
Answer:3/x+1 - 1/x-1

5.Write the form of the partial fraction decomposition of the rational expression.
x^2-x+2/x(x-1)^2
Answer:2/x-1/x-1+2/(x-1)^2

6.. Find the equation of the parabola y = ax2 + bx + c that passes through the points (0, 3), (1,4), and (2, 3).
Answer:y=-x^2+2x+3

7.Write the form of the partial fraction decomposition of the rational expression.
1/9x^2-4
answer: 1/3x+2+1/3x-2

8.An object moving vertically is at the given heights at the specified times. Find the position equation
s = at2 + v0t + s0 for the object given the following conditions.

answer: s=-16t^2+64t+0

1 answer

for the row echelon stuff, enter your data here to check your results:

http://www.math.odu.edu/~bogacki/cgi-bin/lat.cgi

2-7 look ok

#8 is missing data, but the equation looks typical. Must be for a flight from ground level at 64 ft/s