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 = \(\frac{1}{30}\)

tìm x biết 

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

1 : x - 0.5 + 0.4 : x = 18 + 0.3

( 1 - 0.5 + 0.4 ) : x = 17.7

0.9 : x = 17.7

       x = 0.9 : 17.7

      x = \(\frac{3}{59}\)

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❤

Do \(x⋮18,x⋮48\Rightarrow x\in BC\left(18;48\right)\)
Ta có:
\(18=2.3^2\)
\(48=2^4.3\)
\(\Rightarrow BCNN\left(18;48\right)=2^4.3^2=144\)
\(\Rightarrow BC\left(18;48\right)=\left\{0;144;288;...\right\}\)
Mà \(100< x< 200\)
\(\Rightarrow x=144\)

x ⋮ 18; x ⋮ 48

=> x thuộc BC(18; 48)         (1)

18 = 2.32

48 = 24.3

BCNN(18; 48) = 24.32 = 144

BC(18; 48) = B(144) = {0; 144; 288; ...} mà 100 < x < 200

=> x = 144

a. 100 + x = 987

x = 987 – 100

x = 887

b. 204 – x = 18 : 6

204 – x = 3

x = 204 – 3

x = 201

c. x × 5 = 450 – 420

x × 5 = 30

x = 30 : 5

x = 6

=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