Find the values of y which makes the expression (2y + 7) / (y2 - 2y - 15) undefined?

A) - 5, 3

B) - 5, - 3

C) 5, 3

D) 5, - 3

E) 15, - 3

The given expression becomes undefined when y=5 or y = - 3. The answer is option D.

Step-by-step explanation:

The value of the given expression becomes undefined when the denominator equals 0.

Hence to find the value of y which makes the expression undefined, we can equate the value of the denominator to zero and solve it.

Step 1

Equate the denominator to 0.

y^{2} - 2y - 15 = 0

Step 2

Solve the above equation to get the value of y.

y^{2} - 2y - 15 = 0

=> (y-5) (y+3) = 0 [ Roots of the quadratic equation]

=> y = 5 or y = - 3.

Hence when y = 5 or y = - 3 the denominator becomes 0, which makes the expression (2y+7) / 0 and hence it is undefined.