Question

Determinati ecuatia dreptei determinata de punctele :A(2,3) si B(1,5)!

Answer 1

 

$\displaystyle\bf\\Se~dau~punctele:~~A(2,3)~~si~~B(1,5)\\\\Se~cere~ecuatia~dreptei~care~trece~prin~A~si~B. \\\\Rezolvare:\\\\Folosim formula:\\\\\frac{y-y_1}{y_2-y_1}=\frac{x-x_1}{x_2-x_1}\\\\unde~(x_1,y_1)~si~(x_2,y_2)~sunt~coordonarele~punctelor~A~respectiv~B.\\\\\textbf{Scriem ecuatia apoi o aducem la o forma mai simpla.}\\\\\\\frac{y-3}{5-3}=\frac{x-2}{1-2}\\\\\frac{y-3}{2}=\frac{x-2}{-1}\\\\-1(y-3)=2(x-2)\\\\-y+3=2x-4\\\\-y-2x+3+4=0\\\\-y-2x+7=0~~\Big|\times(-1)\\\\\boxed{\bf~y+2x-7=0}$