Find all numbers for which the rational expression is underfined
4/9v+4
4 / [ 9v + 4]
When 9v + 4 = 0 this is undefined
So
9v + 4 = 0 subtract 4 from both sides
9v = -4 divide both sides by 9
v = - 4/9 and this is the value of v that makes the rational function undefined
