The answer and process is shown in the following picture
Answer:
Step-by-step explanation:
let speed of Stephen=x mph
speed of Diana=x+4
then
6x+6(x+4)=276
divide by 6
x+x+4=276/6=46
2x=46-4=42
x=42/2=21
Stephen is traveling at 21 mph.
Diana is traveling at 21+4=25 mph.
A = (Vf - Vi)/t
Multiply by t on both sides to clear the denominator
at = Vf - Vi
Add Vi to both sides.
at +Vi = Vf
Y=36 is the y-intercept simply substitute 0 as x
