x . 3 + 497 = 498,02

=> 3x = 498,02 - 497

=> 3x = 1,02

=> x = 1,02 : 3

=> x = 0,34

~Study well~

#Thạc_Trân

X*3 + 497 = 498,02

X*3          = 498,02 - 497

X*3          = 1,02

X             = 1,02 : 3

X             = 0,34

 Vậy x = 0,34
 

\(11-\left(15-49\right)=-x+\left(9-25\right)\)

\(11-15+49=-x+9-25\)

\(x=9-25-11+15-49\)

\(x=-61\)

Vậy \(x=-61\)

\(x-+\left(-479-479\right)=-\left(26-74\right)\)

\(x+479+479=-26+74\)

\(x=74-26-479-479\)

\(x=-910\)

Vậy \(x=-910\)

479-X x 5= 224

       X x 5= 479-224

       X x 5= 255

       X      = 255:5

       X      = 51

479-X x 5= 224

       X x 5= 479-224

       X x 5= 255

       X      = 255:5

       X      = 51

40793.96757982241

bài này dễ 

bằng 40793.96757982241

hiệu hai số đó là:

12000+ 735-265= 12470 

Nếu sai mong bn thông cảm!

Bài 2: 

a) 2079+ 3186 + 3921 + 2814

= ( 2079+3186 ) + ( 3921+ 2814)

=    5265            +     6735

=        12 000

20 x 479 x 6

= ( 20 x 6 ) x 479

= 120 x 479

= 57480

406

mik kb rồi chỉ cần bạn chấp nhận thôi nha !

x + 73 = 479

x         = 479 - 73

x         = 406

\(1.x-\dfrac{2}{3}\times\left(x+9\right)=1\)

\(x-\dfrac{2}{3}\times x-6=1\)

\(x\times\left(1-\dfrac{2}{3}\right)=7\)

\(x\times\dfrac{1}{3}=7\)

\(x=21\)

\(2.x-\dfrac{11}{15}=\dfrac{3+x}{5}\)

\(\dfrac{15x}{15}-\dfrac{11}{15}=\dfrac{9+3x}{15}\)

\(15x-11=9+3x\)

\(12x=20\)

\(x=\dfrac{5}{3}\)

Bài 15:

a: 2x+x=45

=>3x=45

=>\(x=\frac{45}{3}=15\)

b: 2x+7x=918

=>\(x\cdot\left(7+2\right)=918\)

=>9x=918

=>\(x=\frac{918}{9}=102\)

c: 2x+3x=60+5

=>5x=65

=>\(x=\frac{65}{5}=13\)

d: \(11x+22x=33\cdot2\)

=>33x=66

=>\(x=\frac{66}{33}=2\)

Bài 14:

a: (12-x)(2-x)=0

=>\(\left[\begin{array}{l}12-x=0\\ 2-x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=12\\ x=2\end{array}\right.\)

b: (x-33)(11-x)=0

=>\(\left[\begin{array}{l}x-33=0\\ 11-x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=33\\ x=11\end{array}\right.\)

c: (21-x)(12-x)=0

=>\(\left[\begin{array}{l}21-x=0\\ 12-x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=21\\ x=12\end{array}\right.\)

d: (50-x)(x-150)=0

=>\(\left[\begin{array}{l}50-x=0\\ x-150=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=50\\ x=150\end{array}\right.\)

Bài 13:

a: (x-2)(x-3)=0

=>\(\left[\begin{array}{l}x-2=0\\ x-3=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=2\\ x=3\end{array}\right.\)

b: (x-3)(x-4)=0

=>\(\left[\begin{array}{l}x-3=0\\ x-4=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3\\ x=4\end{array}\right.\)

c: (x-7)(6-x)=0

=>\(\left[\begin{array}{l}x-7=0\\ 6-x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=7\\ x=6\end{array}\right.\)

d: (x-3)(x-13)=0

=>\(\left[\begin{array}{l}x-3=0\\ x-13=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3\\ x=13\end{array}\right.\)