Đáp án là A

Đáp án là A

2x –35 = 15

2x = 15 + 35

2x = 50

x = 50 : 2

x = 25.

Vậy x = 25.

a)  x + 27 = 9 ⇔ x = 9 − 27 ⇔ x = − 18

b)  x – 35 = 15 ⇔ x = 15 + 35 ⇔ x = 50.

c)  − 13 −   x = 39 ⇔ −   x = 39 + 13 ⇔ − x = 52 ⇔ x = − 52.

a, x = -8 - 3 = -11

b, 35 + x = 27 + 12 = 39

=> x = 39 - 35 = 4

c, 2^x = 31 - 15 = 16 

=> x = 4

\(a\)) \(3+x=-8\)

\(x=-8-3\)

\(x=-11\)

a: =>16/x=-4/5

hay x=-20

b: =>x+7/15=-2/3

=>x+7=-10

hay x=-17

X + (- 35 ) = 18

X - 35 = 18

       X = 18 + 35

       X = 53

Vậy X = 53

- 2x -(- 17)= 15

- 2x + 17 = 15

- 2x = 15 - 17

- 2x = - 2

    x = - 2 : ( - 2 )

    x = 1

Vậy x = 1

1) x+ (-35)=18

<=> x-35=18

<=> x=53

2) -2x-(-17)=15

<=> -2x+17=15

<=> -2x=-2

<=> x=1

a)X + (- 35 ) = 18

x = 18 + 35

x = 53

b)- 2x -(- 17)= 15

-2x = 15 - 17

-2x = -2

x = 1

hok tốt!!!

\(a.\)

\(\dfrac{-28}{35}=\dfrac{16}{x}\)

\(\Rightarrow x=\dfrac{35\cdot16}{-28}=\dfrac{5\cdot7\cdot4\cdot4}{-7\cdot4}=-20\)

\(b.\)

\(\dfrac{x+7}{15}=\dfrac{-24}{36}\)

\(\Rightarrow x+7=\dfrac{15\cdot-24}{36}=\dfrac{5\cdot3\cdot-12\cdot2}{12\cdot3}=-10\)

\(\Leftrightarrow x=-17\)

a.\(3+x=-8\)
\(x=-8-3\)
\(x=-11\)
b.\(\left(35+x\right)-12=27\)
\(35+x=27+12\)
\(35+x=39\)
\(x=39-35\)
\(x=4\)
c.\(2^x+15=31\)
\(2^x=31-15\)
\(2^x=16\)
\(2^x=2^4\)
\(x=4\)

câu a : 

3 + x = -8

x = -8 - 3

x = -11

câu b : 

(35 + x) - 12 = 27

35 + x = 39

x = 39 - 35

x = 4

câu c : 

2^x + 15 = 31

2^x = 31 - 15

2^x = 16

x = \(\sqrt{16}\) = 4