Question

{15+2×[4+3×(15×18+81:3-5-5-5)]-1400}×3

42+18×{50+3×[21+2×(529-8×48)-12×2]-900}-43

2013+[23×43+(212×18-93×31)-49×7]

Answer 1

{15+2×[4+3×(15×18+81:3-5-5-5)]-1400}×3=
{15+2x[4+3x(270+27-5-5-5)]-1400}x3=
[15+2x(4+3x282)-1400]x3=
[15+2x(4+846)-1400]x3=
(15+2x850-1400)x3=
(15+1700-1400)x3=
315x3=945