Question

ct%20%5C%3A%20of%20%5C%3A%20r" id="TexFormula1" title="y = \frac{x - r}{x + r?} find \: the \: subject \: of \: r" alt="y = \frac{x - r}{x + r?} find \: the \: subject \: of \: r" align="absmiddle" class="latex-formula">
find the value of r if y=3,and x=3.
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Answer 1

Answer:

r=-3/2=-1.5

Step-by-step explanation:

$y=\frac{x+r}{x-r}\\\text{At} \ x=3\ \text{and} \ y=3\\3=\frac{3-r}{3+r}\\3*(3+r)=(3-r)\\9+3r=3-r\\6=-4r,\ r=-3/2=-1.5$