Elimination Level 1

First Question

9x - 9y = -99x - 9y = -9

9x - 9y = -99x - 9y = -9 (cancel -9y)

9x        = -99x        = -9 | ÷ -9

-x         = 11x         = 1  | + x

0          = 12x        = 1+x

If 12x = 0, then x = 0 but 1+x = 1+0 = 1 so 0 = 0 = 1 is not true. Hence there are no solutions

 

Second Question

(-8x + 9y) = 11 + (- 8x + 9y) = 11                | -(- 8x + 9y) on all sides

0 = 11 + 0 = 11

0 = 11 = 11

0 ≠ 11

 

No solutions

First question:

 

9x - 9y = -99x - 9y = -9

That implies: x - y = -11x - y = -1

x - y = -11x - y

x = -11x

1 = -11

That means you can't divide by x because you get a strange result..... That means x = 0.

0 - y = -1, y = 1.

Therefore \(x = 0, y= 1\)

 

Second question:

-8x + 9y = 11 - 8x + 9y = 11

Only know that you cannot subtract a number which is not 0 and then get the same results...... 

Therefore no solution.