=>x+3x+3.5=75

=>4x+15=75

=>4x=75-15

=>4x=60

=>x=60/4=15

đs= 15

75:(x+3)=5

(x+3)=75:5

(x+3)=15

x=15-3

x=12

x=12

tick nhéthuythumattrangvatoxinomatna

75/x=5/3

75:5=15

suy ra x=3x15=45

 \(\frac{75}{x}=\frac{5}{3}\)

=>\(75.3=5x\)

=>225=5x

=> x=45

tk ủng hộ

x = 75 * 3 : 5 = 45

\(75:\left(2x+16\right)-3=5\)

\(\Rightarrow75:\left(2x+16\right)=5+3\)

\(\Rightarrow75:\left(2x+16\right)=8\)

\(\Rightarrow2x+16=\dfrac{75}{8}\)

\(\Rightarrow2x=\dfrac{75}{8}-16\)

\(\Rightarrow2x=-\dfrac{53}{8}\)

\(\Rightarrow x=-\dfrac{53}{8}:2=-\dfrac{53}{8}.\dfrac{1}{2}\)

\(\Rightarrow x=-\dfrac{53}{16}\)

Ta có :

75 : (2x + 16) - 3 = 5

=> 75 : (2x + 16) = 8

=> 2x + 16 = 75/8

=> x = (75/8 - 16) : 2 

=> x = - 53/16

Ta có :

(x + 1) + (x + 2) + (x + 3) + (x + 4) + (x + 5) + (x + 6) = 75 

=) 6x + ( 1 + .... + 6 ) = 75

=) 6x + [ ( 1 + 6 ) x 6 / 2 ] = 75

=) 6x + 21 = 75

=) 6x = 75 - 21

=) 6x = 54

=) x = 54 : 6 

=) x = 9

Mình nhanh nhất nha 

x+1+x+2+x+3+x+4+x+5+x+6=75

x.6+(1+2+3+4+5+6)=75

x.6+21=75

x.6=75-21=54

x=54:6=9

x+1+x+2+x+3+x+4+x+5+x+6=75

x+x+x+x+x+x+1+2+3+4+5+6=75

x*6+21                                 =75

x*6                                       =75-21

x*6                                       =54

x                                          =54:6=9

a) 6x + 15 = 75

6x = 75 - 15

6x = 60

x = 60 : 6

x = 10

b) x - 12 = (-27)

x = (-27) + 12

x = -15

c) 23 + (x - 5) : 4 = 3⁸ : 3⁵

23 + (x - 5) : 4 = 3³

23 + (x - 5) : 4 = 27

23 + (x - 5) = 27 x 4

23 + (x - 5) = 108

x - 5 = 108 - 23

x - 5 = 85

x = 85 + 5

x = 90

a) 26                  b) 13
c) 36;48;60      d) 5

a) 2.(x+4)+5=65

2.(x+4)=65-5

2.(x+4)=60

x+4=60:2

x+4=30

x=30-4=26

b)(x-5)2=16

x+5=16:2

x+5=8

x=8-5=3

x=645

x-125x9=94

x-1125=94

x=94+1125=1219

a)x=645
b)x=1219
Tick cho mình nha Nguyễn Thị Bích
 

a, x=645

b, x=1219