Answer:

Step-by-step explanation:
=
We need a common denominator before we can add.
+
means the same thing as
-
= 
Y=-1/3x-.75
why:
y-intercept is -.75 five or take.
slope is down 1, over 3
since line (going left to right) is going down, it’s negative
Since the second equation gives a value for a, we can substitute it into the other equation to find a value for B.
Let's substitute b-2 into the first equation wherever there is an a.
a - 3b = 4
(b-2) - 3b = 4
b - 2 - 3b = 4
-2 - 2b = 4
-2b = 6
b = -3
Now let's find a by substituting -3 into either of the equations to find the value of a.
a = b - 2
a = -3 - 2
a = -5
So your solution set is (-5, -3)
Answer:
It will take them 5 hours.
Step-by-step explanation:
If one is moving towards the other at 30, and the other by 20 more, then the equation would be 30+50, so 80mph.