solve for "x"

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Across
  1. 2. What type of operations to use to solve for the variable.
  2. 4. A number and a variable.
  3. 6. Opposite of division.
  4. 7. Opposite of addition.
Down
  1. 1. Opposite of multiplication.
  2. 3. A number by itself.
  3. 5. A missing number.
  4. 8. Opposite of subtraction.