Question 1 • (AG Q4) Keystone Algebra 1 Block: 25-26 (DDiamond)
A system of two linear equations has exactly one solution when the two lines intersect at one point. Different slopes guarantee that the lines cross once, so choices C and E describe systems with one solution. Equivalent equations and lines lying on top of each other represent the same line and have infinitely many solutions; lines that stay the same distance apart are parallel and have no solution.
AI-written and checked against the verified answer.