Answer:
t=2
Step-by-step explanation:
The slope is given by
m = (y2-y1)/(x2-x1)
We have points (3,10) and (5,t) and the slope is -4
Substituting these in
-4 = (t-10)/ (5-3)
Simplifying
-4 = (t-10) / 2
Multiply by 2 on both sides
-4 = (t-10) / 2 *2
-8 = t-10
Add 10 on both sides
-8+10 = t-10+10
2 = t