Question

find number that arent the domain if the function
f(y)=(2y-9)/(7y+6)

Answer 1

the number for which the denominator of f(y) equals to 0 will NOT be in the domain.
so, can you solve, 7y+6= 0 ?

Answer 2

6/7?

Answer 3

almost!
try once again ? hint : be careful with signs.

Answer 4

oh ok its negative 6/7

Answer 5

thats correct,
so x=-6/7 is the number not in the domain of f(y)
thats it!
any doubts ?

Answer 6

** y= -6/7

Answer 7

ok so just solve for the denominator to be undefined I got it

Answer 8

good, well actually there are 2 things to consider in GENERAL,
1) denominator should NOT= 0
2) the quantity under the square root sign must be NON-NEGATIVE
here there was no square root sign, so we just considered 1).

Answer 9

and solve for denominator to be ZERO
for which f(y) is undefined....