2.25%X*1*20%=36-搜答案-搜狗做题网

X+1-3X=5X+10 6-3X=5X-20

X+1-3X=5X+105x+3x-x=-10+17x=-9x=-9/76-3X=5X-205x+3x=20+68x=26x=13/4一、已知M-N=3,则9-2M+2N==9-2（M-N）=9-6=

1)x-10=4(x-28)x-10=4x-1123x=102x=342)3(x-28)=x+56+283x-3*28=x+2*28+282x=6*28x=3*28x=843)2(1.5x-30-20

(X-X*20%-18)-（X-X*20%-18）*10%=X*1/2-3则（X*80%-18）*90%=X*1/2-372%*X-16.2=X*1/2-322%*X=13.2X=60

2.5%X+20*2.25%-2.25%X=0.4850.25%X+20*2.25%=0.4850.25%X=0.485-20*2.25%0.25%X=0.485-0.450.25%X=0.035X=

(1)12x+36-6x=102则：6x=66所以：x=11(2)2x-48-x=54,即：x=54+48=102(3)2x-1+x=14,即：3x=15,所以：x=5

(2*3)^(x+1)=36^x6^(x+1)=6^2x所以x+1=2xx=1

1/4X=13X=5210/3X=20/21X=2/70.72X=12.96X=18

x【x+1】的平方-x【x的平方-3】-2【x+1】【x-1】=20x³+2x²+x-x³+3x-2x²+2=204x+2=204x=18x=4.5

x-1/7x*4=36,

x-1/7x*4=36x-4/7x=363/7x=36x=84

x/2+x/8+x/12+x/20=1

60X+15X+10X+6X=12091X=120X=120/91

x/2+x/6+x/12+x/20+x/30+x/42=136x/42=1x=7/6

1/x+1/x-30=1/20 x=?

1/x+1/(x-30)=1/20[(x-30)+x]/[x(x-30)]=1/2020(2x-30)=x^2-30xx^2-30x-40x+20*30=0x^2-70x+600=0(x-10)(x-

1.5X+20=1X（50-X)1,5x+20=50-x1.5x+2=50-202.5x=30x=12

20%(x+5)=四分之一x-10.2x+1=0.25x-10.05x=2x=40

12481632

(1)x-80%x=620%x=6x=30(2)x+20%x=2.41.2x=2.4x=2(3)5x+6=365x=30x=6

x-(1/5+1/5)x-39=39x-2/5x=39+393/5x=78x=78÷3/5x=130x-1/4x-2/5x=112(1-1/4-2/5)x=1127/20x=112x=112÷7/20

当然不是,去括号后会出现平方,是一元二次方程

（1-1/2）X+(1/2-1/3)X+(1/3-1/4)X+(1/4-1/5)X+(1/5-1/6)X+(1/6-1/7)X=1(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-

25%x+(1-25%)*20%x+6=x

25%x+(1-25%)*20%x+6=x0.25x+0.15x+6=x0.4x+6=xx-0.4x=60.6x=6x=10