Question 211251
Find all numbers for which:{{{3/(7z+5)}}} is undefined.
The expression is undefined for all values of z that will make the denominator equal to zero (division by zero is "undefined")
Set the denominator to zero and solve for z:
{{{7z+5 = 0}}} Subtract 5 from both sides.
{{{7z = -5}}} Divide both sides by 7.
{{{highlight(z = -5/7)}}} 
Your answer is absolutely correct!