Step 1: Add equation A and equation B. Why? Because the y-coefficients are opposites. Can you see them?
Is it a shortcut to cheating, or a necessary scaffold for learning? Here is a proper guide on how to utilize the Kumon Level I Solution Book effectively.
Linear functions and their graphsSystems of linear equationsSimplifying algebraic expressionsFactoring polynomialsQuadratic equations and the quadratic formulaInequalities