A)
1ère façon:
A=-3+(4-5+2)-4
=-3+(1)-4
=-6
2ème façon :
A=-3+(4-5+2)-4
=-3+4-5+2-4
=-6
B)
1ère façon :
B = - 17 - (-6-3) - 8
=-17-(-9)-8
=-17+9-8
=-16
2ème façon :
B = - 17 - (-6-3) - 8
=-17+6+3-8
=-16
C)
1ère façon :
C =-1-(-2-(-3 ÷ 4 - 5)- 6)-7
=-1-(-2-(-3-20)/4)-6)-7
=-1-(-2-(-23/4) -6)-7
=-1-(-8+23/4)-7
=-1-(-32+23)/4-7
=-1-(-9)/4-7
=-1+9/4 -7
=-8+9/4
=-23/4
2ème façon :
C =-1-(-2-(-3 ÷ 4 - 5)- 6)-7
=-1-(-2+3/4+5)-6)-7
=-1+2-3/4-5+6-7
=-13+8-3/4
=-5-3/4
=-23/4