Quick math help

Can someone please check my math Hw? Thank you!!
Solve each system by elimination.

1. 8x+7y=-1
-9x-7y=2
I got (-1,1)
2. 4x+3y=1
-4x-7y=-13
I got (2,-2)
3. -7x-6y=-21
-x-6y=-3
I got (3,0)
4. -2x+3y=-16
-2x-5y=-16
I got (8,0)
5. -7x+2y=13
-14x+4=26
I got (0,0)
6. 15x-8y=14
-5x+9y=8
I got (2,2)
7. x-6y=22
-2x+3y=1
I got (-8,-5)
8. 2x+10y=30
-10x-6y=-18
I got (0,3)
9. -35x-15y=0
56x+24y=0
I got (0,0)
10. -56x+72y=-16
-49x+63y=-14
I need help with this one!!!

asked by Anonymous
  1. You do not need us to check.
    Put your answers back in the original equations.
    as for #10
    -56x+72y=-16
    -49x+63y=-14

    divide top by 2
    divide second by 7
    -7 x + 9 y = -2
    -7 x + 9 y = -2
    NO solution. This is the same line repeated, no intersection
    In linear algebra if one row is identical to or a multiple of another, the determinant of the coefficient matrix is zero and the solution is undefined.

    posted by Damon
  2. Can you check number 5? Is it no solution?

    posted by Anonymous

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