Mad Math

1234567
Across
  1. 2. 67-28+6-40=
  2. 3. 4/7+2/3=
  3. 5. 34+8-6+15
  4. 7. 23x30÷10=
Down
  1. 1. 8/20 into a decimal
  2. 2. 34+8-6+15
  3. 4. (7+3)x(12-5)
  4. 6. 36≥X² 34-x=in the twenties X=?