Learning goals: Teacher Facing Describe (orally) a linear equation as having “one solution”, “no solutions”, or “an infinite number of solutions”, and solve equations in one variable with one solution. Describe (orally) features of linear equations with one solution, no solution, or an infinite number of solutions. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 8.4 Linear Equations and Linear Systems, Grade 8.