Question
If 2x + 3y = 19 and 3x - 2y = 9, then the value of
x2 + y2 is:Solution
ATQ, 2x + 3y = 19 3x - 2y = 9 Multiply first by 2: 4x + 6y = 38 Multiply second by 3: 9x - 6y = 27 Add: 13x = 65 x = 5 Now, 2(5) + 3y = 19 10 + 3y = 19 3y = 9 y = 3 So, x2 + y2 = 25 + 9 = 34
Two cars start from a place with a speed of 50 km/hr at an interval of 12 minutes. What is the speed of a man coming from the opposite direction towards...
Train A takes 24 seconds to cross a pole and 20sec to cross a man walking at the speed of 5.6 meter per second towards it. Train B travels 1 meter per s...
Length of a train, whose speed is 84 km/h, is 420 metres. Find the time taken (in seconds) by train to cross a bridge of length 280 metres.
- Train 'A' having a speed of 20 m/s can cross a man in 5 seconds. The length of train 'B' is 100 metres more than the length of 'A'. If the speed of 'B' is ...
Two trains running in opposite directions cross a pole in 25 seconds and 15 seconds respectively and they cross each other in 21 seconds.Find the ratio ...
A train has 15 coaches and an engine. Each coach is 24 metres and the engine is 48 metres. Time taken by the train to cross a platform, whose length is ...
Length of a train is three-fourths of the length of a platform. If the train crosses the platform in 63 seconds, then find the time taken by train to c...
A train 120 m long passes a man standing on a platform in 8 seconds. What time (in seconds) will it take to pass completely over a platform 180 m long a...
How many seconds will a train 60 m in length, travelling at the rate of 40 km an hour, take to pass another train 80 m long, proceeding in the same dire...
Train M, ‘x’ metres long crosses (x – 30) metres long platform in 22 seconds while train N having the length (x + 30) metres crosses the same plat...
Relevant for Exams:
