We are given with two equations and is asked to determine the solution of the system of linear equation. via elimination, we add the two equations to eliminate 3x, this means y should be equal to 9 and from the first equation, x should also be equal to 9, too
The average speed is the ratio between the distance covered, and the time elapsed to cover that distance.
The total distance is the sum of the three distances covered:

Similarly, the total time elapsed is

So, althought you didn't always travelled with the same speed, you globally covered 170km in 1.75 hours. This leads to an average speed of

I believe when it's a fraction.
Answer:
A) 
Step-by-step explanation:


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** From what the problem said, we know that we selected the correct equation.
I am joyous to assist you anytime.
It would be 123,456,789 (if not counting decimals)
decimals would be like 0.123456789