If (0.2x+0.3y=2.7) and (0.4x-0.1y=1.1), what is the value of (y)?
Answer and explanation
Correct answer: 43/7
Multiplying both equations by 10 gives 2x+3y=27 and 4x−y=11. From the second equation, y=4x−11. Substituting this into the first equation gives 2x+3(4x−11)=27, so 14x=60 and x=30/7. Therefore, y=4(30/7)−11=43/7. Hence, option A is correct. Exam tip: remove decimals carefully and verify the value in both original equations; an integer-looking distractor such as 5 or 6 is not necessarily correct.
Frequently asked questions
What is the correct answer to this question?
43/7
Why is this the correct answer?
Multiplying both equations by 10 gives 2x+3y=27 and 4x−y=11. From the second equation, y=4x−11. Substituting this into the first equation gives 2x+3(4x−11)=27, so 14x=60 and x=30/7. Therefore, y=4(30/7)−11=43/7. Hence, option A is correct. Exam tip: remove decimals carefully and verify the value in both original equations; an integer-looking distractor such as 5 or 6 is not necessarily correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Pair of Linear Equations in Two Variables. Topic: Algebraic methods: Substitution method and Elimination method..
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.