Answer:
use desmos to figure it out.
I'd suggest using "elimination by addition and subtraction" here, altho' there are other approaches (such as matrices, substitution, etc.).
Note that if you add the 3rd equation to the second, the x terms cancel out, and you are left with the system
- y + 3z = -2
y + z = -2
-----------------
4z = -4, so z = -1.
Next, multiply the 3rd equation by 2: You'll get -2x + 2y + 2z = -2.
Add this result to the first equation. The 2x terms will cancel, leaving you with the system
2y + 2z = -2
y + z = 4
This would be a good time to subst. -1 for z. We then get:
-2y - 2 = -2. Then y must be 0. y = 0.
Now subst. -1 for z and 0 for y in any of the original equations.
For example, x - (-1) + 3(0) = -2, so x + 1 = -2, or x = -3.
Then a tentative solution is (-3, -1, 0).
It's very important that you ensure that this satisfies all 3 of the originale quations.
Answer: His average speed for his total journey from York to Blackpool is approximately 61.41 km/h.
Step-by-step explanation:
Since, The distance covered by him from York to Leeds = 45 km,
The speed when he covered this distance = 54 km/ h
Thus, the time taken by him in travelling from York to Leeds = 45/54 hours (Because, Time = Distance/speed)
Now, The distance covered by him from Leeds to Blackpool = 42 km,
The time taken by him in travelling from Leeds to Blackpool = 35 minutes = 35/60 hours
Hence, the total time taken by him in this journey
hours
And, the total distance he covered= 45 + 42 = 87 km
Thus, His average speed
