Question

Find the value for the variable that makes the expression undifined. X2 -9 X2-7x+10

Answer 1

an equation is undefined, when its denominator is 0, or turns to 0, because we can't divide anything by 0.

so let's simply set the denominator of this one = 0.

$\bf x^2-7x+10=0\implies (x-2)(x-5)=0\implies x= \begin{cases} 2\\ 5 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{(2)^2-9}{(2)^2-7(2)+10}\implies \cfrac{-5}{-10+10}\implies \cfrac{-5}{0}\leftarrow und efined \\\\\\ \cfrac{(5)^2-9}{(5)^2-7(5)+10}\implies \cfrac{16}{-10+10}\implies \cfrac{16}{0}\leftarrow und efined$