Answer:
?
Step-by-step explanation:
where are the options?
Answer: Raju travels at a higher speed.
Step-by-step explanation:

Speed inversely proportional to time.
As time taken to cover a particular distance decreases the speed will increase.
Raju covers a certain distance in 1 hour.
Sham covers the same distance in 2 hours.
1< 2
Thus Raju travels at a higher speed.
Answer:
See explanation below
Step-by-step explanation:
The best explanation is noticing that in order to get from the point R (12, 1) to the point Q (7, 4) we move 5 units to the left and 3 units up. And to go from point Q (7, 4) to point P (2, 7) we do exactly the same: move 5 units to the left and 3 units up. That means that these points are all connected via the same rate of change: - 3/5, which is in fact the slope of the line the three points belong to.
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.