100%:x-50%:x+40%:x=18+30%:x

<=> (100% - 50% + 40%) : x = 18 + 30% : x

<=> 90% : x = 18 + 30% : x 

=> 90% : x - 30% : x = 18

=> (90% - 30%) : x = 18

<=> x = 60% : 18

=> x = \(\frac{1}{30}\)

a; 100% : \(x\) - 50% : \(x\) + 40% : \(x\) = 18 + 30% : \(x\)

   (100% - 50% + 40%): \(x\) = 18 + 30% : \(x\)

                            90% : \(x\)  = 18 + 30% : \(x\)                  

                           90%: \(x\)  - 30%: \(x\) = 18

                          60% : \(x\) = 18

                                   \(x\) = 60% : 18

                                    \(x\) = \(\dfrac{1}{30}\)

    100%x-50%:x+40%:x=18+30%:x

<=>x-x/2+2/5x=18+3/10x

<=>10x²-5x²+4=180x+3

<=>10x²-5x²+4-180x-3

<=>5x²-180x+1=0

Denta=(-180)²-4.5.1=32380

Phương trình có 2 nghiệm phân biệt :

x¹=180+căn32380/10;x²=180-căn32380/10

100%:x-50%:x+40%:x=18+30%:x

<=> (100% - 50% + 40%) : x = 18 + 30% : x

<=> 90% : x = 18 + 30% : x 

=> 90% : x - 30% : x = 18

=> (90% - 30%) : x = 18

<=> x = 60% : 18

=> x = 1/30

Học tốt nha! Love❤

Cảm ơn nhà Mik tick rồi

=1x0.5:X+0.4:X = 18+0.3:X

=0.5:X+0.4:X = 18+0.3:X

=(0.5+0.4):X = 18+0.3:X

=0.9:X = 18+0.3:X

18=(0.9-0.3):X

18=0.6:X

X=18:0.6

X=30

a) x +60+40 =400

   x             = 400-40-60

   x             =300

b) (x+25) + 50 = 100:2 +30

(x+25) +50     = 50+30=80

x+25             = 80-50=30

x                   =30-25

x                  = 5

a.x+60+40=200

x+100=200

x=200-100

x=100

b.x+25+50=100:2+30

x+75=50+30

x+75=80

x=80-75

x=5

mk nhanh nhất

a) x + 100 = 200

    x           = 200 - 100

    x           = 100

b) x + 25 + 50 = 50 + 30

    x + 75          = 80

    x                  = 80 - 75

    x                  = 5

100% : x - 50% : x + 40% : x = 18 + 30% : x

100% : x - 50% : x + 40% : x - 30% : x = 18

( 100% - 50% + 40% - 30% ) : x = 18

60% : x = 18

x = 60% : 18

x = 3/5 . 1/18

x = 1/30

Vậy x = 1/30