Question

Find the equation of the line that passes through the points (-800,200)and(-400,300).

Answer 1

`(-800,200), \ \ \ \(-400,300) \\ \\ first \ find \ the \ slope \ of \ the \ line \ thru \ the \ points \: \\ \\ m= (y-y_(1))/(x-x_(1) ) \\ \\m=(200-300 )/(-800+400) = (-100)/(-400)=(1)/(4) \\ \\Now \ use \ y = mx + b \ with \ either \ point \ to \ find \ b, \ the \ y-intercept \ : \\ \\ y=mx+b \\ \\200= (1)/(4) \cdot(-800)+b\\ \\200=-200 +b \\ \\b=200+200=400 \\ \\ y= (1)/(4)x+400 \ is \ the \ answer`