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Find the equation of a line through 2 points. The line is not vertical.
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", "advice": "\\[ \\begin{align*} \\frac{y-y_1}{x-x_1} &= \\frac{y_2-y_1}{x_2-x_1}\\\\ \\frac{y-(\\var{y1})}{x-(\\var{x1})}&=\\frac{\\var{y2}-(\\var{y1}) }{\\var{x2}-(\\var{x1})} \\\\ \\frac{\\var{yminusy1e}}{\\var{xminusx1e}} &=\\var{expression(string(rational((y2-y1)/(x2-x1))))}\\\\ \\var{yminusy1e}&=\\var{expression(string(rational((y2-y1)/(x2-x1))))}(\\var{xminusx1e})\\\\ \\textrm{So }\\qquad y&=\\var{expression(string(rational((y2-y1)/(x2-x1))))}(\\var{xminusx1e}) +\\var{y1}\\\\&=\\var{eqn} \\end{align*}\\]
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