6-3 Bellwork Solve each system by using substitution 1.) 7x – 2y = 1 2y = x -1 2.) 2x + 3y = 144 y – x = 24

Bellwork Solve for y 1.) 2x -4y = 8 2.) – x + y = 2 Solve for x

6-3 (Part 1) - Solving Systems by Elimination Algebra 1

When to use Add. Or Subt. to eliminate a variable for linear combination Use addition to eliminate a variable when the coefficients are opposites. Use subtraction to eliminate a variable when the coefficients are the same.

Example 1 - Solve 4x-3y=11 2x+3y=13 (4, 5/3)

Example 2 - Solve 8a+b=1 8a-3b=3 (3/16, -1/2)

Example 3 – Arranging like terms x + 3y = 12 -3y + x = 30

Example 4 – Arranging like terms y = x – 9 x + 8y = 0