The equation of a line in slope form is given by;
y=mx + c where m is the slope of the line and c is the y-intercept
Given points (2,1) and m=5 , take an imaginary point on the line (x,y)
Then to get slope m, the formula is;
m=change in y coordinates/change in x coordinates
m=y-1/x-2
5=y-1/x-2 --------multiplied both sides of the equation by x-2
5(x-2)=y-1
5x-10 = y-1 ------collect like terms
5x=y-1+10
5x=y+9 -------re-write the equation in the correct form as
5x-9 =y
y= 5x-9