1) 15 - (3 + 7) + 20 = 15 - 11 2) 6 + 5 * 3 - 7 + 4 =6+15- 3) 6(70 + 30) = 70 + 300 4) 18 - 15/3 + (2/3) / 3 = 14 5) (3 + 4)(8 + 2) -(4+0)*(2+3 6) 3 + 4(6 - 3 * 2) * 6 -3*2* 7) 14 / (15 + 21 - 18 - 16) 8) 8 - 3(4 - 2) + 12 / (3 * 2 - 4) 9) 15 + 12(8 + 2) 10) (9 * 4 - 2 * 6); (2 * 4 - 30 * 0)