6-3x+5x-30=-98

-24+2x=-98

2x=(-98)+24=-74

x=(-74):2=-37

Nhớ t..i..c..k nha

<=>6 -3x +5x -30 =-98

<=>6+2x=-68

<=>2x=-74

<=>x=-37

<=>6 -3x +5x -30 =-98

<=>6+2x=-68

<=>2x=-74

<=>x=-37

\(a, 3\left(2-x\right)+5\left(x-6\right)=-98\Leftrightarrow6-3x+5x-30=-98\)

                                                            \(\Leftrightarrow2x=-74\)

                                                             \(\Leftrightarrow x=-37\)

\(b,\)\(\Leftrightarrow x^2+1=0\left(v\text{ô} nghi\text{ệm}\right)ho\text{ặc} 49-x^2=0\)

     \(\Leftrightarrow x=7 ho\text{ặc} x=-7\)

Chúc bạn học tốt ^_^

a)3(2-x)+5(x-6)=-98

6-3x+5x-30=98

-3x+5x      =98+30-6

x(-3+5)      =122

x.2            =122

x               =122:2=61

b)(x^2+1)(49-x^2)=0

=>x²+1=0 hoặc 49-x²=0

x²=-1(vô lí)hoặc x²     =49

=>x=7

a)3(2-x)+5(x-6)=-98

6-3x+5x-30=-98

-3x+5x      =-98+30-6

x(-3+5)      =-74

x.2            =-74

x               =122:2=-37

b)(x^2+1)(49-x^2)=0

=>x²+1=0 hoặc 49-x²=0

x²=-1(vô lí)hoặc x²     =49

=>x=7

\(a.3.\left(2-x\right)+5.\left(x-6\right)=-98\)

\(6-3x+5x-30=-98\)

\(6+2x-30=-98\)

\(2x-24=-98\)

\(2x=-98+24\)

\(2x=-74\)

\(x=-37\)

Vậy \(x\in\left\{-37\right\}\)

a) 6-3x+5x-30=-98

2x=-98+30-6

2x=-74

x=-74/2

x=-37

1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 10
x = 2
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x + 8 = 11x - 10
-9x = -18
x = 2

2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 14
x = 2

7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 10
x = 10/7

3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 0
x = 0

8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
x + 22 = 10x - 15
9x = 37
x = 37/9

4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 2

9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
2x + 1 = 11x - 6
-9x = -7
x = 7/9

5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 8

10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
35 = 6 + 4x
4x = 29
x = 29/4

a) \(3\left(2-x\right)+5\left(x-6\right)=98\)

\(\Rightarrow6-3x+5x-30=98\)

\(\Rightarrow\left(6-30\right)+\left(-3x+5x\right)=98\)

\(\Rightarrow-24+2x=98\)

\(\Rightarrow2x=98-\left(-24\right)\)

\(\Rightarrow2x=122\)

\(\Rightarrow x=122:2\)

\(\Rightarrow x=61\)

Vậy x = 61

b) \(3x-2=2x-3\)

\(\Rightarrow3x-2x=2-3\)

\(\Rightarrow x=-1\)

Vậy x = -1

c) \(\left(x-7\right)\left(x^3-8\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-7=0\\x^3-8=0\end{cases}}\Rightarrow\orbr{\begin{cases}x-7=0\\x^3=8\end{cases}}\Rightarrow\orbr{\begin{cases}x=7\\x=2\end{cases}}\)

Vậy x = 7 hoặc x = 2

_Chúc bạn học tốt_

a.6-3X+5X-30=98

2X-24=98

2X=74

X=37

b.3X-2X=2-3

X=-1

c.X-7=0 X=7

   X^3-8=0 X=2

\(\Leftrightarrow6-3x+5x-30=-98\\ \Leftrightarrow2x=-74\\ \Leftrightarrow x=-37\)

\(3\left(2-x\right)+5\left(x-6\right)=-98\\ 6-3x+5x-30=-98\\ 2x-24=-98\\ 2x=-74\\ x=-37\)

a)

Ta có : ( 1 + 2 + 3 + ... + 99)

Số số hạng là:       ( 99 - 1 )  : 1 + 1 = 100

Tổng là:                 ( 99 + 1 ) x 100 : 2 = 5000

=> 5000 x ( 13  - 12 - 1 ) x 15

=> 5000 x 10 x 15

=> 50000 x 15

=> 750000

Ko muốn vt nx :))

khó thế 

(1-2+3-4+.....-98+99)x(2013x6-2013-2013x5)

=(1-2+3-4+....-98+99)x[ 2013x(6-1-5)]

= (1-2+3-4+....-98+99)x(2013x0)

= (1-2+3-4+....-98+99)x0 = 0

=0

1. \(x-8+32=68\)

\(x-8=68-32\)

\(x-8=36\)

\(x=36+8\)

\(x=44\)

_____

2. \(x+8+32=68\)

\(x+8=68-32\)

\(x+8=36\)

\(x=36-8\)

\(x=28\)

_____

3. \(98-x+34=43\)

\(98-x=43-34\)

\(98-x=9\)

\(x=98-9\)

\(x=89\)

_____

4. \(98+x-34=43\)

\(98+x=43+34\)

\(98+x=77\)

\(x=77-98\)

\(x=-21\)

_____

5. \(x:5:4=800\)

\(x:5=800.4\)

\(x:5=3200\)

\(x=3200.5\)

\(x=16000\)

_____

6. \(18+x=384:8\)

\(18+x=48\)

\(x=48-18\)

\(x=30\)

_____

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

\(84,6-2.x=5,1.3,02\)

\(84,6-2.x=15,402\)

\(2.x=84,6-15,402\)

\(2.x=69,198\)

\(x=69,198:2\)

\(x=34,599\)

_____

8. \(x\times5=120:6\)

\(x.5=20\)

\(x=20:5\)

\(x=4\)

_____

9. \(\left(15\times24-x\right):0,25=100:0,25\)

\(\left(15.24-x\right):0,25=400\)

\(15.24-x=400.0,25\)

\(15.24-x=100\)

\(360-x=100\)

\(x=360-100\)

\(x=260\)

1,x-8+32=68

=>x-8=68-32=36

=>x=36+8=42

2,x+8+32=68

=>x+8=68-32=36

=>x=36-8=28

3,98-x+34=43

=>98-x=43-34=9

=>x=98-9=89

4,98+x-34=43

=>98+x=43+34=77

=>x=77-98=-21

5,x:5:4=800

=>x:20=800

=>x=800x20=16000

6,18+x=384:8=48

=>x=48-18=30

7,(84,6-2x):3,02=5,1

=>84,6-2x=5,1x3,02=15,402

=>2x=84,6-15,402=69,198

=>x=69,198:2=34,599

8,5x=120:6=20

=>x=20:5=4

9,(15x24-x):0,25=100:0,25=400

=>360-x=400x0,25=100

=>x=360-100=260.

1. \(...\Rightarrow x+24=68\Rightarrow x=68-24=44\)

2. \(...\Rightarrow x+40=68\Rightarrow x=68-40=28\)

3. \(...\Rightarrow3^{2\left(8+x\right)}=9=3^2\Rightarrow2\left(8+x\right)=2\Rightarrow8+x=1\Rightarrow x=-7\)

4. \(...\Rightarrow3^{2\left(8+x\right)}=77\) (bạn xem lại đề)

5. \(...\Rightarrow x:5=800.4\Rightarrow x:5=3200\Rightarrow x=3200.5=16000\)

6. \(...\Rightarrow18+x=48\Rightarrow x=48-18=30\)

7. \(...\Rightarrow84,6-2x=5,1.3,02=15,402\Rightarrow2x=84,6-15,402\Rightarrow2x=69,198\Rightarrow x=34,599\)

8. \(...\Rightarrow5.x=20\Rightarrow x=20:5=4\)

9. \(\left(360-x\right):0,25=400\Rightarrow360-x=400.0,25=100\Rightarrow x=400-100=300\)