Solving Two and Multi Step Equations

Two-Step Equations A two-step equation is an equation that has two operations. You will continue to use inverse operations to solve two-step equations. You will do “reverse order of operations” when “undoing”.

3x – 8 = 7 “Get rid” of the number being added to or subtracted from the variable first using inverse operations. Add 8 to both sides 3x – 8 + 8 = 7 + 8 3x = 15 Get rid of the coefficient (divide both sides by 3)

3x – 8 = 7 X = 5

2.7x + 3.4 = 19.6 Subtract 3.4 from both sides. 2.7x + 3.4 – 3.4 = 19.6 – 3.4 2.7x = 16.2 Divide both sides by 2.7 X = 6

Multi Step Equations Remember that you are solving equations by UNDOING all the operations in the reverse order that they would have been done. Look at the problem, think about order of operations, and work in reverse order. Does any simplifying need to happen first? If so, do that first!!

Example -2(7 – c) = 6 Distribute the -2 -14 + 2c = 6 Add 14 to both sides -14 + 2c + 14 = 6 + 14 Simplify 2c = 20 Divide both sides by 2 2c/2 = 20/2 C = 10

x – 3(x + 1) = 17 Distribute the -3 X – 3x – 3 = 17 Simplify Add 3 to both sides -2x – 3 + 3 = 17 + 3 -2x = 20 Divide both sides by -2 -2x/-2 = 20/-2 X = -10

Try these… 2x + 29 – 8x = 5 3(x – 9) = 30 3x – (6 – x) = -22

Try these…answers 2x + 29 – 8x = 5 x = 4 3(x – 9) = 30 x = 19 x = 25/4 or 6 ¼