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The pair of linear equations 2x+3y=8 and 4x+6y=16 have:
Exactly one solution
No solution
Infinitely many solutions
Two distinct solutions
Infinitely many solutions
Given: Equations: 2x + 3y = 8 and 4x + 6y = 16
Equations: 2x + 3y = 8 and 4x + 6y = 16
Δ=2436=0
Check if the second equation is an exact multiple of the first by comparing the ratios of coefficients.
Assuming a unique solution without testing for proportional coefficients leads to a wrong answer.
Identify proportionality
Observe that the coefficients of the second equation are exactly twice those of the first: 4=2×2, 6=2×3, 16=2×8.
4=2×2,6=2×3,16=2×8
Compute determinant
For a system ax+by=c and dx+ey=f, the determinant Δ=ae−bd tells if the lines are parallel (Δ=0) or intersecting (Δ=0). Here a=2, b=3, d=4, e=6.
Δ=2×6−3×4=12−12=0
Conclude nature of solutions
Since Δ=0 and the constant terms are also in the same ratio (16 = 2×8), the equations represent the same line, giving infinitely many solutions.
Infinite solutions because the equations are dependent
C is correct because the two equations are proportional, representing the same line and thus have infinitely many solutions.
In matrix form, a zero determinant indicates rank deficiency; similar checks are used for solving linear equations in higher dimensions.