Question 191713
First find slope 
 the formula is:
 m=(y₂-y₁ )⁄(x₂-x₁)
 m= (4-3)/(3-1)
m=1/2
 now use this formula to find an equation:
 y-y₁ =m(x-x₁)
y-3=1/2(x-1)
 y-3=1/2*x-1/2
y=1/2*x-5/2