\(\Rightarrow x\times\left(1+\frac{3}{10}\right)=6,3+2,8\)

\(\Rightarrow x\times1,3=9,1\)

\(\Rightarrow x=\frac{9,1}{1,3}\)

\(\Rightarrow x=7\)

có đóng ngoặc mở ngoặc ko bạn

Ta có :   \(X\left(\frac{3}{10}+1\right)=6,3+2,8\)

              \(X\)x

\(X\left(\frac{3}{10}+1\right)=6,3+2,8\)

x+x.2,7+x.6,3=120

x.1+x.2,7+x.6,3=120

x.(1+2,7+6,3)=120

x.    10            =120

x=120:10

x=12

x.(1+2,7+6,3)=120

x.10=120

x=120:10

x=12

chúc bạn học tốt !!!!

=>x.(1+2,7+6,3)=120

xx10=120

x=120:10

x=12

a)Xx(8,75+1,25)=26,3

Xx10=26,3

=>X=26,3:10=2,63

A)=Xx(8.75+1.25)=26.3

=Xx10=26.3

=X=26.3:10

=X=2.63

B)X=1.3

C)X=3.6

D)X=62.5

E)X=0.55

F)X=1.6

 Câu b.c.d.e.f tự làm nhé có đáp án rồi 

làm hết luôn mới t i c k :3

\(\left(84,6-2\cdot x\right):3,02=5,1\)

\(\Rightarrow84,6-2\cdot x=15,402\)

\(\Rightarrow2\cdot x=69,198\)
\(\Rightarrow x=69,198:2\)

\(\Rightarrow x=34,599\)

_____________

\(\left(15\cdot24-x\right):0,25=100:0,25\)

\(\Rightarrow\left(360-x\right):0,25=400\)

\(\Rightarrow360-x=100\)

\(\Rightarrow x-360-100\)

\(\Rightarrow x=260\)

______________

\(128\cdot x-12\cdot x-16\cdot x=5200\)

\(\Rightarrow x\cdot\left(128-12-16\right)=5200\)

\(\Rightarrow x\cdot100=5200\)

\(\Rightarrow x=5200:100\)

\(\Rightarrow x=52\)

__________________

\(5\cdot x+3,75\cdot x+1,25\cdot x=20\)

\(\Rightarrow x\cdot\left(5+3,75+1,25\right)=20\)

\(\Rightarrow10\cdot x=20\)

\(\Rightarrow x=20:10\)

\(\Rightarrow x=2\)

\(x\cdot3,7+x\cdot6,3=360:120\)

\(\Rightarrow x\cdot\left(3,7+6,3\right)=3\)

\(\Rightarrow x\cdot10=3\)

\(\Rightarrow x=\dfrac{3}{10}\)

__________________

\(x\cdot23-6\cdot23+x\cdot69=320\)

\(\Rightarrow x\cdot\left(23+69\right)=320+6\cdot23\)

\(\Rightarrow x\cdot92=458\)

\(\Rightarrow x=458:92\)

\(\Rightarrow x=\dfrac{229}{46}\)

___________________

\(\left(x+1\right)\left(x+2\right)=72\)

\(\Rightarrow x^2+2x+x+2=72\)

\(\Rightarrow x^2+3x+2=72\)

\(\Rightarrow x^2+3x+2-72=0\)

\(\Rightarrow x^2+3x-70=0\)

\(\Rightarrow x^2+10x-7x-70=0\)

\(\Rightarrow\left(x-7\right)\left(x+10\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=7\\x=-10\end{matrix}\right.\)

___________________

\(\left(x+2\right)\cdot16\cdot x=160x\)

\(\Rightarrow16x^2+32x=160x\)

\(\Rightarrow16x^2+32x-160x=0\)

\(\Rightarrow16x^2-128x=0\)

\(\Rightarrow16x\left(x-8\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=8\end{matrix}\right.\)

Đổi:

f.x.23-6.23+x.69=230

=>23.(x-6+3x)=230

=>4x-6=10

=>4x=10+6

=>4x=16

=>x=4

h.(x+2).16.x=160.x

=>(16x+32).x = 160x

=>16x^2 + 32x = 160x

=>16x^2 = 128x

=>16x^2 - 128x=0

=>x(16x-128)=0

=>x=0 hoặc 16x-128=0

+)x=0=>x=0

+)16x-128=0

=>16x=128

=>x=8

X x 1,1 + X : 2,5 = 12

X x 1,1 + X x 0,4 = 12

X x ( 1,1 + 0,4 ) = 12

X x 1,5 = 12

        X = 12 : 1,5

        X = 8

\(x\times100567=1467171963\)

                       \(x=1467171963\div100567\)

                       \(x=14589\)

Vậy x=14589

Easy!

Let the bass kick! O-oooooooooo AAAAE-A-A-I-A-U- JO-oooooooooooo AAE-O-A-A-U-U-A- E-eee-ee-eee AAAAE-A-E-I-E-A- JO-ooo-oo-oo-oo EEEEO-A-AAA-AAAA O-oooooooooo AAAAE-A-A-I-A-U- JO-oooooooooooo AAE-O-A-A-U-U-A- E-eee-ee-eee AAAAE-A-E-I-E-A- JO-ooo-oo-oo-oo EEEEO-A-AAA-AAAA O-oooooooooo AAAAE-A-A-I-A-U- JO-oooooooooooo AAE-O-A-A-U-U-A- E-eee-ee-eee AAAAE-A-E-I-E-A- JO-ooo-oo-oo-oo EEEEO-A-AAA-AAAA-O----------

X x 2, 8 + X x 5, 2 = 48

2X = 48 : ( 2, 8 + 5, 2 )

2X = 6

X = 6 : 2

X = 3

~ Chúc bạn học tốt ~

X x 2,8 + X x 5,2 =48

X x [2,8+5,2]      =48

X x   8                =48

      X                  =48:8

       X                 =6

là 3 nhé bạn

Giải 
X + X : 5 x 7,5 + X : 2 x 9 = 315 
X + 7,5 X / 5 + 9 X / 2 = 315 
X + 1,5 X + 4,5 X = 315 
7X = 315 
X = 315 : 7 
X = 45

Xx1+Xx1:5x7,5+Xx1:2x9=315

Xx1+Xx0,2x7,5+Xx0,5x9=315

Xx1+Xx1,5+Xx4,5=315

Xx(1+1,5+4,5)=315

Xx7=315

X=315:7

X=45

\(x+x:5\cdot7,5+x:2\cdot9=315\)

\(x+x:\left(5:7,5\right)+x:\left(2:9\right)=315\)

\(x+x:\frac{10}{15}+x:\frac{2}{9}=315\)

\(x+x\cdot\frac{3}{2}+x.\frac{9}{2}=315\)

\(x\left(1+\frac{3}{2}+\frac{9}{2}\right)=315\)

\(x\left(\frac{2}{2}+\frac{3}{2}+\frac{9}{2}\right)=315\)

\(7x=315\)

\(x=315:7\)

\(x=45\)