a: =>x-27,7=12

=>x=39,7

b: =>73,2:x=3

=>x=24,4

\(a,\Rightarrow x+2=-40\\ \Rightarrow x=-42\\ b,\Rightarrow6x-7-2x=5\\ \Rightarrow4x=12\Rightarrow x=3\\ c,\Rightarrow68-56-x=-2\\ \Rightarrow12-x=-2\\ \Rightarrow x=14\)

a,\(2,5.16,27.4+7,3=16,27.10+7,3=162,7+7,3=170\)

b,\(8.6.10+4.25.12+3.16.31+2.34.24=48.10+48.25+48.31+48.34\)

\(=48.\left(10+25+31+34\right)=48.100=4800\)

c,\(78.31+78.24+78.17+22.72=78\left(31+24+17\right)+22.72=78.72+22.72\)

\(=72.\left(78+22\right)=72.100=7200\)

d,\(102.67-34.51=102.67-17.102=102.\left(67-17\right)=102.50=5100\)

đéo hiểu thì cút nhé đéo ai khiến m trả lời cả . ngu thì nói ngu đi đừng bày đặt t ghét nhất là cái loại như m đấy ạ 

Bài 2 

a, \(1-\left(12,5+x-4,25\right):21,75=0\)

\(=>21,75-12,5-x+4,25=0\)

\(=>13,5-x=0=>x=13,5\)

b,\(x.101-x+72.99+72=21050\)

\(=>100x+72.100=21050\)

\(=>100\left(x+72\right)=21050\)

\(=>x+72=210,5\)\(=>x=138,5\)

c,\(151-2\left(x-6\right)=2227:17\)

\(=>151-2\left(x-6\right)=131\)

\(=>2\left(x-6\right)=20\)

\(=>2x=32=>x=16\)

d,\(\left(x+4\right)+\left(x+6\right)+\left(x+8\right)+...+\left(x+26\right)=210\)\(=>12x+\left(4+6+8+...+26\right)=210\)

\(=>12x+180=210=>12x=30\)

\(=>x=\frac{30}{12}=\frac{15}{6}=\frac{5}{2}\)

a, 8,7- X = 5,3 + 2

    8,7 - X = 7,3

            X = 8,7 - 7,3 

           X = 1,4

b, X x 5,3 = 9,01 x 4

   X x 5,3  = 36,04

   X          = 36,04 : 5,3

   X         = 6,8

259,2 : X = 39 + 4,2

259,2 : X = 43,2

           X = 259,2 : 43,2

           X = 6

X - 27,7 = 35,51

X           = 35,51 + 27,7

X            = 63,21

tk mình nhé !

ai k mình mình k lại

thank you very much

bye bye

259,2:X=39+4,2                         X-27,7=5,3x6,7

259,2:X=43,2                             X-27,7=35,51

X=259,2:43,2                             X=35,51+27,7 

X=6                                           X=63,21

kick minh nhe

a) \(101x-x+72.99+72=21050\)

\(100x+72.\left(99+1\right)=21050\)

\(100x+72.100=21050\)

\(\left(x+72\right).100=21050\)

\(x+72=210,5\)

\(x=138,5\)

b) \(x:4+x:0,125=9,9\)

\(x:\left(4+0,125\right)=9,9\)

\(x:4,125=9,9\)

\(x=40,8375\)

c) \(1,5x-5,7=5,3\)

\(1,5x=11\)

\(x=\frac{22}{3}\)

a) (100 + 67) x 67 + (200 - 33) x 33

= 167 x 67 + 167 x 33

= 167 x (67 + 33)

= 167 x 100

= 16700

b) 45,651 x 73 + 45,651 x 20 + 45,651 x 7

= 45,651 x (73 + 20 + 7)

= 45,651 x 100

= 4565,1

c) 14,2 x 30 + 14,2 x 57 + 14,2 x 13

= 14,2 x (30 + 57 + 13)

= 14,2 x 100

= 1420

a) (100 + 67) × 67 + (200 - 33) × 33

= 167 × 67 + 167 × 33

= 167 × 100

= 16700

b) 45,651 × 73 + 45,651 × 20 + 45,651 × 7

= 45,651 × (73 + 20 + 7)

= 45,651 × 100

= 4565,1

c) 14,2 × 30 + 14,2 × 57 + 14,2 × 13

= 14,2 × (30 + 57 + 13)

= 14,2 × 100

= 1420

a: =>4(x-3)=49-1=48

=>x-3=12

=>x=15

b: =>123-5(x+4)=38

=>5(x+4)=123-38=85

=>x+4=17

=>x=13

c: =>2x-138=9*8=72

=>2x=72+138=210

=>x=105

Đk: \(x\ge4\)

\(A=\sqrt{x+4\sqrt{x-4}}+\sqrt{x-4\sqrt{x-4}}\)

\(=\sqrt{\left(x-4\right)+4\sqrt{x-4}+4}+\sqrt{\left(x-4\right)-4\sqrt{x-4}+4}\)

\(=\sqrt{\left(\sqrt{x-4}+2\right)^2}+\sqrt{\left(\sqrt{x-4}-2\right)^2}\)

\(=\sqrt{x-4}+2+\left|\sqrt{x-4}-2\right|\)

TH1:\(\sqrt{x-4}>2\Leftrightarrow x>8\)

\(A=\sqrt{x-4}+2+\sqrt{x-4}-2=2\sqrt{x-4}\)

TH2:\(\sqrt{x-4}\le2\Leftrightarrow4\le x\le8\)

\(A=\sqrt{x-4}+2-\left(\sqrt{x-4}-2\right)=4\)

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