Question
Quantitative Aptitude Question on Linear & Quadratic Equations
If x and y are real numbers such that 4x2+4y2−4xy−6y+3=0, then the value of (4x+5y) is
Answer
We can rewrite the given equation as: (2x−y)2+3(y−1)2=0
For this equation to hold true, both terms must be equal to zero: (2x−y)2=0 and (y−1)2=0
Solving these equations, we get: x=21 and y=1
Therefore, 4x+5y=4(21)+5(1)=7
So, the value of (4x+5y) is 7.
Explanation
Solution
We can rewrite the given equation as: (2x−y)2+3(y−1)2=0
For this equation to hold true, both terms must be equal to zero: (2x−y)2=0 and (y−1)2=0
Solving these equations, we get: x=21 and y=1
Therefore, 4x+5y=4(21)+5(1)=7
So, the value of (4x+5y) is 7.