Question

what is the slope of the line passing through the points (1, –5) and (4,1)

Answer 1

$(x_1;\ y_1);\ (x_2;\ y_2),\ the\ slope\ m=\dfrac{y_2-y_1}{x_2-x_1}$

$(1;-5)\to x_1=1;\ y_1=-5\\(4;\ 1)\to x_2=4;\ y_2=1$

subtitute

$m=\dfrac{1-(-5)}{4-1}=\dfrac{1+5}{3}=\dfrac{6}{3}=2$