三道计算题,快

题目

三道计算题,快
1-{1-[1-16/5*(--5/16)]*3}/（-1）
2-[1-(1/2*2/3-1)]*(-0.75)*(-0.75)+(-0.5)*(-0.5)*(-0.5)*5*5
1/2/[(-0.5)*(-0.5)*(-0.5)-(-1.5)* (-1.5)]+3/2/3/4*(-2)

答案

1-{1-[1-16/5*(-5/16)]*3}/（-1）
=1+{1-[1-16/5*(-5/16)]*3}
=1+[1-(1+1)*3]
=1+(1-6)
=-4
2-[1-(1/2*2/3-1)]*(-0.75)*(-0.75)+(-0.5)*(-0.5)*(-0.5)*5*5
=-[1-(1/3-1)]*(-3/4)*(-3/4)+(-1/2)*(-1/2)*(-1/2)*5*5
=-(3/5)*(-3/4)*(-3/4)+(-1/2)*(-1/2)*(-1/2)*5*5
=-27/80-25/8
=-27/80-250/80
=-277/80
1/2/[(-0.5)*(-0.5)*(-0.5)-(-1.5)* (-1.5)]+3/2/3/4*(-2)
=(1/2)/(-0.125-2.25)-(3/2)/(3/2)
=(1/2)*(8/19)-1
=4/19-1
=-15/19