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1Solving 2-Step Equations

Step 1: Start with the number attached to the variable through addition or subtraction

• 2x + 7 = 21

Step 2: Do the inverse operation (the opposite of how it is attached).                 

• 2x + 7 = 21
•       -7   

Step 3: What you do to one side of the equal sign, you do to the other.

• 2x + 7 = 21
•       -7    -7
• 
  
• 2x = 14

Step 4: Figure out how the number is attached to the variable.

• 2x = 14 (2 is attached to the x by multiplication)

Step 5: Do the inverse (opposite) operation of how it is attached to both sides.

•  2x = 14
•   2      2
• x = 7

After we solve the problem, we can replace the variable with the answer we got and double check our work.  2(7) +7 = 21