The system 4x − 6y = 10 and 2x − 3y = k has infinitely many solutions. What is the value of k?

Question

Accepted Answer

A. 5. Halving the first equation gives 2x − 3y = 5, so the two equations coincide exactly when k = 5.

Answer

B. 10 — k = 10 keeps the first equation's constant without halving it; the lines would be parallel and distinct.

Answer

C. 20 — k = 20 doubles instead of halving.

Answer

D. −5 — k = −5 has the wrong sign.

Algebra practice question