Can anyone with either one of these

slope-point form:
we need the slope (m) and a point.
y-y₀=m(x-x₀)
Given two point A(x₁,y₂) and B(x₂,y₂), the slope of the line  is :
m=(y₂-y₁) /(x₂-x₁)

Example 3:
we can take two points:
A(12,2)
B(13,7)
m=(7-2) / (13-12)=5/1=5

therefore:
y-2=5(x-12)
y-2=5x-60
y=5x-60+2
y=5x-58

y=5x-58

Example 4:
we can take two points.
A(0,0)
B(3,1)
m=(1-0)/(3-0)=1/3

Therefore:
y-0=1/3(x-0)
y=x/3

y=x/3

21 is the answer the answer is 21