September 1, 2020 Solving Systems with Elimination

Solve the system of equations using the elimination method. 8x + y = −16−3x + y = −5 Add the equations: What equation do you get? 11x = -21 11x=-11 8x=-21 8x=-11 Solve for the remaining variable: What is the value of x? -2.625 -1.9090... -1.375 -1 Substitute your solution into one of the equations: Write your new equation below: Solve for the other variable: What is the value of y? -8 -27 -37 8 Write your solution as a coordinate point (x, y). Solve the system of equations using the elimination method. −4x + 9y = 9x − 3y = −6 Multiply one or both equations to have one set of matching coefficients: Choose ALL of the possible new systems that could be used to solve the original system. −4x + 9y = 94x − 12y = −36 −4x + 9y = 93x − 9y = −18 −4x + 9y = 92x − 6y = −12 −8x + 18y = 188x − 24y = −48 Add the equations: Which of the following equations could not be used to solve for one of the variables? -x=-9 -6x=-30 -3y=-27 -2x+3y=-3 Solve for the remaining variable: Write your answer below, either x=# or y=#. Substitute your solution into one of the equations: Write your equation with the substitution below. (ex. (2)-3y=-6, if x=2) Write your solution as a coordinate point (x, y). Solve the system of equations using the elimination method. 2x + 8y = 6−5x − 20y = −15 Multiply one or both equations to have one set of matching coefficients: Choose ALL of the possible new systems that could be used to solve the original system. 5x + 20y = 15−5x − 20y = −15 10x + 40y = 30−10x − 40y = −30 2x + 8y = 6−2x − 8y = −6 20x + 80y = 60−20x − 80y = −60 Add the equations: What happens when you add the equations together? What does this tell you about the solution?