Solving two-step linear equations using addition and subtraction: ax + b = c

Lessons

1. Find x in the equation modelled by each diagram.
   1. 
      
      
   2. 
      
      
2. Find x in the equation modelled by algebra tiles.
   1. 
      
      
   2. 
      
      
3. Solve.
   1. $7x + 9 = 21$
   2. $98 - 2x = 14$
   3. $- 35 = 6x + 49$
   4. $- 4x - 11 = 109$
4. The total admission fee of an aquarium for 30 students is $240 after a group discount of $3 for each person. What is the original admission fee before the discount?