All of them you can really struggling with thisSolution1 2x

All of them you can. really struggling with this.

1) 2x / (5x - 25 )

value of x for which expression is no defined would be all values of x which makes denominator equal to 0

so setting the denominator equal to 0 and solving for x

5x - 25 = 0

adding 25 on both sides

5x = 25

x = 5

therefore, at x = 5 function would be undefined

2) ( y - 8 ) / (y^2 - 64 )

again function would be undefined for values of y that makes denominator equal to 0

so setting denominator equal to 0 and solving for y

y^2 - 64 = 0

adding 64 on both sides

y^2 = 64

y = + - 8

hence, function would be undefined for y = + 8 and y = - 8

3) ( y^2 + 9y + 14 ) / (y^2 + 10y + 21 )

factroing the top and bottom expression

y^2 + 9y + 14 = (y+2)(y+7)

y^2 + 10y + 21 = ( y+3)(y+7)

hence, expression becomes

(y+2)(y+7) / ( y+3)(y+7)

cancelling the common factor from top and bottom we are left with

(y+2) / (y+3)