6x + 7y = 28 2x + 2y = 10The solution to the given system of equations is (x, y). What is the value of y ?
Correct answer: A. -2
- A. -2
- B. 7
- C. 14
- D. 18
Explanation
First, let's rearrange the second equation to solve for y. Multiply both sides by 2 to get:4x + 4y = 20Now we can eliminate x by subtracting the second equation from the first equation:(6x + 7y) - (4x + 4y) = 28 - 202x + 3y = 8Subtracting corresponding terms gives:2x - 4x + 3y - 4y = 8 - 20- 2x - y = - 12Now solve for y:- y = - 12 + 2xy = 12 - 2xWe can substitute this value of y into the second equation:2x + 2(12 - 2x) = 102x + 24 - 4x = 10- 2x + 24 = 10- 2x = - 14x = 7Now substitute the value of x into the equation we found for y:y = 12 - 2(7)y = 12 - 14 y = -2So the solution to the system of equations is (x, y) = (7, -2). Therefore, the value of y is -2.
Last updated
About Quantitative Reasoning
Quantitative reasoning applies arithmetic and basic algebra to numerical relationships, including percentages, ratios, averages, fractions, proportions, profit and loss, rates, time, work and measurement. Questions focus on translating words into equations, choosing an efficient method and checking whether the result is numerically reasonable.
Practise Quantitative Reasoning
505 free Quantitative Reasoning MCQs from Analytical and Logical Reasoning, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Analytical and Logical Reasoning questions like this
Analytical and Logical Reasoning is on 24 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
(1/2x+1) + 5Which of the following is equivalent to the expression above for x > 0?
1/400 in percentage =
100 oranges are bought at the rate of Rs. 350 and sold at the rate of Rs. 48 per dozen. The percentage of profit or loss is:
100 oranges are bought at the rate of Rs. 350 and sold at the rate of Rs. 48 per dozen. The percentage of profit or loss is:
|14| * |-2|=?