Mathematics

Mathematics

Problem

The equations 2x+3y+5=02x + 3y + 5 = 0 and 4x+6y+1=04x + 6y + 1 = 0 are written in standard form. Explain briefly why this pair does not have a unique solution.
Intuitive explanation

These two equations represent lines in the plane, and a unique solution exists only when the lines intersect at exactly one point. Notice that the second equation's left side is almost exactly twice the first—the coefficients of xx and yy follow the pattern 4=2(2)4 = 2(2) and 6=2(3)6 = 2(3). This means the lines are parallel (same slope), but the constant terms don't follow this doubling pattern (1≠2(5)1 \neq 2(5)), so they're distinct parallel lines that never meet. No intersection means no solution.

Intuitive explanation

These two equations represent lines in the plane, and a unique solution exists only when the lines intersect at exactly one point. Notice that the second equation's left side is almost exactly twice the first—the coefficients of xx and yy follow the pattern 4=2(2)4 = 2(2) and 6=2(3)6 = 2(3). This means the lines are parallel (same slope), but the constant terms don't follow this doubling pattern (1≠2(5)1 \neq 2(5)), so they're distinct parallel lines that never meet. No intersection means no solution.

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