slope intercept from two points

Answer:
-2x+6.
Step-by-step explanation:
1) if A(1;4), B(2;2), then the required equation is:
2) [tex]\frac{x-X_A}{X_B-X_A} =\frac{y-Y_A}{Y_B-Y_A}; \ => \ \frac{x-1}{2-1}=\frac{y-4}{2-4}; \ => \ \frac{x-1}{1}=\frac{y-4}{-2};[/tex]
3) if to re-write this equation as slop-interception form, then:
y= -2x+6.