Quick math help
posted by Anonymous on .
Can someone please check my math Hw? Thank you!!
Solve each system by elimination.
1. 8x+7y=1
9x7y=2
I got (1,1)
2. 4x+3y=1
4x7y=13
I got (2,2)
3. 7x6y=21
x6y=3
I got (3,0)
4. 2x+3y=16
2x5y=16
I got (8,0)
5. 7x+2y=13
14x+4=26
I got (0,0)
6. 15x8y=14
5x+9y=8
I got (2,2)
7. x6y=22
2x+3y=1
I got (8,5)
8. 2x+10y=30
10x6y=18
I got (0,3)
9. 35x15y=0
56x+24y=0
I got (0,0)
10. 56x+72y=16
49x+63y=14
I need help with this one!!!

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. 
Can you check number 5? Is it no solution?