System of equations

123456
Across
  1. 3. a symbol for a value we don't know yet
  2. 5. using the solution of a variable to find another variable
  3. 6. getting rid of a variable by using subtraction or addition
Down
  1. 1. to take away
  2. 2. a drawing where you plot points with lines
  3. 4. a process of combining two or more numbers