四道超难一元一次方程题加答案，四道超难有理数整式混合运算及答案（必须是计算题，不是应用题）

Answer 1

1. 33.1-（-22.9）+（-10.5）=33.1+22.9-10.5=56-10.5=45.5 2.（-8）-（-15）+（-9）-（-12）=-8+15-9+12=7-9+12=-2+12 =10 3.-2/3+（-1/6）-（-1/4）-1/2=-2/3-1/6+1/4-1/2=（-2*4-2+3-6）/12=(-8-2+3-6)/12=-13/12 4.3/5-3/2+（-11/4）+13/4 =3/5-3/2-11/4+13/4=(3*4-3*10-11*5+13*5)/20=(12-30-55+65)/20=(-18+10)/20=-8/20=-2/5 5.|141/111-141/99|+|141/111-42/99|=141/99-141/111+141/111-42/99=1 6.已知｜a｜＝3．｜b｜＝4，求a＋b和a－b的值．解：｜a｜＝3．｜b｜＝4 a=3或a=-3 b=4或b=-4 a+b=3+4=7或a+b=3+(-4)=-1或a+b=(-3)+4=1或a+b=(-3)+(-4)=-7 a-b=a+(-b)而|-b|=|b| 所以a-b=7或－7或－1 或1 7.｜a｜＝5，｜b｜＝19，且｜a＋b｜＝－（a＋b），求a－b的值．解：｜a＋b｜＝－（a＋b）即a+b<=0 满足条件的a,b的值是所以a=-5且b=-19 a=5且b=-19 所以a-b=(-5)-(-19)=(-5)+19=14或a-b=5-(-19)=5+19=24 8.（-0.8）+1.2+（-0.7）+（-2.1）+0.8+3.5 =(-0.8+0.8)+(1.2+3.5-0.7)-2.1 =4-2.1 =1.9 9. 1/2+（-2/3）+4/5+（-1/2）+（-1/3） =(1/2-1/2)+4/5-(2/3+1/3) =4/5-1 =-1/5 10. -4.2+5.7-8.4+10 =(5.7+10)-(4.2+8.4) =15.7-12.6 =3.1 11. -1/4+5/6+2/3-1/2 =(5/6+2/3)-(1/4+1/2) =(5/6+4/6)-(1/4+2/4) =9/6-3/4 =3/2-3/4 =6/4-3/4 =3/4 12. 1+7分之1-（-7分之3）=1+1/7+3/7=1+4/7=1又4/7 13. (-9)-(-13)+(-20)+(-2)=-9+13-20-2=-18 14. 3+13-(-7)/6=16+7/6=103/6 15. (-2)-8-14-13=-(2+8+14+13)=-37 16. (-7)*(-1)/7+8=1+8=9 17. (-11)*4-(-18)/18=-44+1=-43 18. 4+(-11)-1/(-3)=4-11+1/3=-9+1/3=-26/3 19.(-1)+4*19+(-2)=-3+76=73 20. (-17)*(-9)-20+(-6)=153-20-6=127