Answer:
50 km/hr
Step-by-step explanation:
D = RT
Time for first part of trip = 80/60 = 4/3 hr.
Time for second part of trip = 20/30 = 2/3 hr.
total time for entire trip = 4/3 + 2/3 = 6/3 = 2 hr.
Total distance = 100 km
Average rate of speed for entire trip = 100/2 = 50 km/hr
The distributive property combines like terms.
2.4 ft/min goes with table 4
10 ft/min goes with table 2
-0.8 ft/min goes with table 1
0.25 ft/min goes with table 3
No solution for this question
Standard Form looks like this:

Also, A cannot be negative and there are no fractions in Standard Form.
Now that we know the rules of Standard Form, let's get x and y on one side.
-2/3y = 2 + 8/15x
Subtract 8/15x from both sides.
-8/15x - 2/3y = 2
Multiply 2/3 by 5/5 to get a common denominator.
-8/15x - 10/15y = 2
Multiply everything by 15 to rid of the fractions.
-8x - 10y = 30
Multiply everything by -1 to make A positive.
8x + 10y = -30
8x + 10y = -30