Question

[´(7-5)x6x(4x3-10)-[3+(4x9-7x5)+3x2]]x2-28. 39x12+[(19x6-14x5)x8-(21x5-7x13)x14]x3. 4x[6x3-[3x(16+9)-2x3+5-18x4]x3]-(29-16+2)x3. [(15-3x4)x5-9]x8-2[13-(5x7-6x4)+4x5].

Answer 1

1) [(7-5)×6×(4×3-10)-[3+(4×9-7×5)+3×2]]×2-28=
={2×6×(12-10)-[3+(36-35)+6]]×2-28
=[12×2-(3+1+6]×2-28
=(24-10)×2-28
=14×2-28
=28-28=0

2) 39×12+[(19×6-14×5)8-(21×5-7×13)×14]×3=
=468+[114-70)8-(105-91)×14]×3
=468+[(44×8)-14×14]×3
=468+(352-196)×3
=468+156×3
=468+468=936

3) 4×{6×3-[3×(16+9)-2×3+5-18×4]×3}-(29-16+2)×3=
=4×[18-(3×25-6+5-72)×3]-15×3
=4×[18-(75-6+5-72)×3]-45
=4×[18-(69-67)×3]-45
=4×(18-2×3)-45
=4×(18-6)-45
=4×12-45
=48-45=3

4) [(15-3×4)×5-9]×8-2[13-(5×7-6×4)+4×5]=
=[(15-12)×5-9]×8-2[13-(35-24)+20]
=(3×5-9)×8-2(13-11+20)
=(15-9)×8-2(2+20)
=6×8-2×22
=48-44=4