12y 2 y 2 + 15y+26 : y 2 - 9y 3y 3 + 39y 2 = start fraction, y, squared, plus, 15, y, plus, 26, divided by, 12, y, squared, end fraction, divided by, start fraction, 3, y, cubed, plus, 39, y, squared, divided by, y, squared, minus, 9, y, end fraction, equals (y+2) (y-9) 36y3 Which values of y make the resulting expression undefined?

The equation is not typed properly, and it is difficult to understand. But it is clear that you are trying to determine the value of y that makes your equation undefined.

An fraction is undefined if it's denominator is zero, that is if it's of the form a/0.

The value that makes a fraction undefined is the value that makes the denominator vanish. The value that makes its denominator equal to zero.

Example:

1. (x - 3) / (y - 5) is undefined if

y - 5 = 0

Or y = 5

2. (3x² + 4xy + 6) / (x + 2) (y + 6)

If x + 2 = 0, or y + 6 = 0

That is if x = - 2, or y = - 6

You can use this idea to find the value of y that makes your equation undefined.