C. % A = 35%; % T =35% ; %G = 15%; X = 15%

a

a)(-25)+15+x=50

(-10)+x=50

x=50-(-10)

x=50+10

x=60

b)(-25)+15+x=-35

(-10)+x=-35

x=(-35)-(-10)

x=(-35)+10

x=-25

c)(-25)+15+x=-10

(-10)+x=-10

x=-10-(-10)

x=-10+10

x=0

dễ tick mik đi rồi giải cho mik thề

a) x = 50 + 25 - 15 = 60

b) x = -35 + 25 - 15 = -25

c) x = -10 + 25 - 15 = 0

b) Thay x=-28

\(\left(-2\right)+17+\left(-28\right)=-13\)

c) Thay x=-4

\(\left(-4\right)+25+\left(-47\right)=-26\)

d) Thay x=8

\(25+8+\left(-13\right)=20\)

\(\dfrac{x-55}{45}+\dfrac{x-30}{35}+\dfrac{x-25}{25}+\dfrac{x-40}{15}=10\)

\(< =>\dfrac{x-55}{45}+\dfrac{x-30}{35}+\dfrac{x-25}{25}+\dfrac{x-40}{15}-10=0\)

\(< =>\dfrac{x-55}{45}-1+\dfrac{x-30}{35}-2+\dfrac{x-25}{25}-3+\dfrac{x-40}{15}-4=0\)

\(< =>\dfrac{x-100}{45}+\dfrac{x-100}{35}+\dfrac{x-100}{25}+\dfrac{x-100}{15}=0\)

\(< =>\left(x-100\right)\left(\dfrac{1}{45}+\dfrac{1}{35}+\dfrac{1}{25}+\dfrac{1}{15}\right)=0\)

\(< =>x-100=0\left(\dfrac{1}{45}+\dfrac{1}{35}+\dfrac{1}{25}+\dfrac{1}{15}\ne0\right)\)

\(< =>x=100\)

15/x = 25/35

15/x = 5/7

15/x = 15/21 ( lấy cả tử và mẫu của phân số 5/7 nhân với 3 )

x = 21

Vậy x = 21

a) \(x\in\left\{1;-1;5;-5;7;-7;35;-35\right\}\)
b) \(x\in\left\{1;-1;3;-3;5;-5;15;-15\right\}\)

c) \(x\in\left\{0;25;50;75\right\}\)

d) Ta có: \(x+16⋮x+1\)

nên \(15⋮x+1\)

\(\Leftrightarrow x+1\in\left\{1;-1;3;-3;5;-5;15;-15\right\}\)

hay \(x\in\left\{0;-2;2;-4;4;-6;14;-16\right\}\)

a) 35 \(⋮\) x \(\Rightarrow\) x \(\in\) Ư(35) = {\(\pm1;\pm5;\pm7;\pm35\)}

b) 15 \(⋮\) x \(\Rightarrow\) x \(\in\) Ư(15) = {\(\pm1;\pm3;\pm5;\pm15\)}

c) x \(⋮\) 25 \(\Rightarrow\) x \(\in\) B(25) = {\(0;25;50;75;100;...\)}

Mà x < 100 \(\Rightarrow\) x \(\in\){\(0;25;50;75\)}

d) x + 16 \(⋮\) x + 1

 \(\Rightarrow\) x + 16 - (x + 1) \(⋮\) x + 1

 \(\Rightarrow\) 15 \(⋮\) x + 1

\(\Rightarrow\) x + 1  \(\in\) Ư(15) = {\(\pm1;\pm3;\pm5;\pm15\)}

\(\Rightarrow\) x \(\in\) {\(0;-2;2;-4;4;-6;14;-16\)}

x = 21

25 /35 =15/x

x *25=35*15

x * 25=525

x       = 525 /25

x       =21

1) 42/35 - [ 33/14 . 21/22 - ( 54/25 : 27/25 - 7/10 )]

= 42/35 - ( 9/4-13/10)

=42/35-19/20

=1/4

2) a) 5/21 . x/34 = 35/102     

x/34=35/102 : 5/21

x/34=49/34

=> x=34

Vậy x=34

b) 15/x . 21/13 = 45/91

15/x=45/91 : 21/13

15/x=15/49

=> x=49

Vậy x=49

lớp 4

2x-15=25

2x=25+15

2x=40

x=40:2

x=20

63:x=21

x=63:21

x=3

x-8=96

x=96+8

x=104

120-(x-3)=35

x-3=120-35

x-3=85

x=85+3

x=88

35-5(x-2)=15

5(x-2)=35-15

5(x-2)=20

x-2=20:5

x-2=4

x=4+2

x=6

(x-9)-20=19

x-9=19+20

x-9=39

x=39+9

x=48

2782:(216-x-3)=15

câu này mk thấy đề sai rồi bạn nha

130-30(x-2)=100

30(x-2)=130-100

30(x-2)=30

x-2=30:30

x-2=1

x=1+2

x=3

chúc bạn học tốt nha

ủng hộ mk bằng cach tk nha

a/ 2x -15 = 25

2x = 25 - 15

2x = 10

x = 10 : 2

x = 5

b/ 63 : x =21

x = 63 : 21

x = 3

c/ x - 8 = 96

x = 96 + 8

x =104

d/ 120 - (x - 3) = 65

 x - 3 = 65

x - 3 = 120 - 65

x - 3 = 55

x = 55 + 3

x = 58

e/ 35 - 5 (x - 2) = 15

5 (x - 2) = 35 - 15

5 (x - 2) = 20

x - 2 = 20 : 5

x - 2 = 4

x = 4 + 2 

x = 6

f/ (x - 9) - 20 = 19

x - 9 = 19 + 20

x - 9 = 39

x = 39 - 9

x = 30

g/ 2782 : (216 - x - 3) = 15 (bài này ra số thập phân bạn nên coi lại)

h/  130 - 30 (x - 2) = 100

30 (x - 2) = 130 -100

30 (x - 2) = 30

x - 2 = 30 : 30

x - 2 = 1

x = 1 + 2

x =3

1) 2x - 15 = 25

➡️2x = 25 - 15 

➡️2x = 10

➡️x = 10 : 2 = 5

2) 63 : x = 21

➡️x = 63 : 21 = 3

3) x - 8 = 96

➡️x = 96 + 8 = 104

4) 120 - (x - 3) = 35

➡️x - 3 = 120 - 35

➡️x - 3 = 85

➡️x = 85 + 3 = 88

5) 35 - 5( x - 2) = 15

➡️5(x - 2) = 35 - 15

➡️5( x - 2) = 20

➡️x - 2 = 20 : 5

➡️x - 2 = 4

➡️x = 4 + 2 = 6

6) (x - 9) - 20 = 19

➡️x - 9 = 19 + 20

➡️x - 9 = 39

➡️x = 39 + 9 = 48

7) 2782 : (216 - x - 3) = 15

➡️216 - x - 3 = 185,5

➡️x = -  216 + 185,5 +3

➡️x = -27,5

8)130 - 30( x - 2) = 100

➡️30( x - 2) = 130 - 100

➡️30( x - 2) = 30

➡️x - 2 = 30 : 30

➡️x - 2 = 1

➡️x = 1 + 2 = 3

2x-15=25

2x=25+15

2x=40

x=40:2

x=20

x-8=96

x=96+8

x=104

120-(x-3)=35

x-3=120-35

x-3=85

x=85+3

x=88

35-5(x-2)=15

5(x-2)=35-15

5(x-2)=20

x-2=20:5

x-2=4

x=4+2

x=6

(x-9)-20=19

x-9=19+20

x-9=39

x=39+9

x=48

782:(216-x-3)=15

hik như câu này đề lỗi

130-30(x-2)=10

30(x-2)=130-10

30(x-2)=120

x-2=120:30

x-2=4

x=4+2

x=6

chúc bạn học tốt nha

ủng hộ mk bằng  cách tk nha