Question 315837
If the rational expression is {{{4/(b+7)}}}, then...



First take the denominator and set it equal to zero to get {{{b+7=0}}}. We're doing this because we want to find the values of 'b' that make the denominator zero (remember, we can't divide by zero).



Solve {{{b+7=0}}} to get {{{b=-7}}}. So the value {{{b=-7}}} makes the rational expression {{{4/(b+7)}}} undefined.