a)-22: b)35: c)84

a)3-[17-x]=289-325

[17-x]=3-(289-325)

[17-x]=3-(-36)

[17-x]=39

x=17-39

x=-22

b)25-[x+5]=-415-[15-415]

25-[x+5]=-415+400

25-[x+5]=-15

[x+5]=25+15

[x+5]=40

x=40-5

x=35

tick mình lên 30 điểm với 

a)-Ix-3I+16=4

-Ix-3I=4-16

-Ix-3I=-12

-IxI=-12+3

-IxI=-9

x=-9

b)3-(17-x)=289-(36+289)

3-(17-x)=289-325

3-(17-x)=-36

(17-x)=3-(-36)

(17-x)=39

x=17-39

x=-22

c)25-(x+5)=415-(15-415)

25-(x+5)=415-(-400)

25-(x+5)=815

(x+5)=25-815

(x+5)=-790

x=(-790)-5

x=-795

d)34+(21-x)=(3747-30)-3746

34+(21-x)=3717-3746

34+(21-x)=-29

31+x=21-(-29)

31+x=50

x=50-31

x=19

a, 3- (17-x) = 289 - (36+289)

3 - (17 - x )= 289 - 325

3 - (17 - x )= -36

17 - x =3 - (-36)

17 - x =39

       x = 17 - 39

       x = -22

b, 25- (x+5) = - 415 - (15 - 415)

25 - ( x + 5)= -415 - (-400)

25-( x + 5 ) =-15

x + 5 = 25 - (-15)

x+5 =40

x = 40 -5

x=35

hok tốt !

1/ a/ \(3-\left(17-x\right)=289-\left(36+289\right)\)

\(3-\left(17-x\right)=-36\)

\(17-x=3-\left(-36\right)\)

\(x=17-39=-22\)

b/ \(25-\left(x+5\right)=415-\left(15-415\right)\)

\(25-\left(x+5\right)=815\)

\(x+5=25-815\)

\(x=\left(-790\right)-5=-795\)

c/ \(\left|x-7\right|+13=25\)

\(\left|x-7\right|=25-13=12\)

\(\left|x-7\right|\Rightarrow\left[{}\begin{matrix}x-7=12\\x-7=-12\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=19\\x=-5\end{matrix}\right.\)

Câu 2:

a) (a - 1) - (a - 3) = a - 1 - a + 3 = 2

b) (2 + b) - (b + 1) = 2 + b - b - 1 = 1

a) x=22

b)x=-795

c)x=84

a) x - 22

b) = - 795

c) =84

Cái này là toán lớp 1 sao?

a) 3 - (17 - x) = 289 - (36 + 289)

3 - (17 - x) = 289 - 325

3 - (17 - x) = -36

17 - x = -36 - 3

17 - x = -39

x = -39 + 17

x = -22

b) 25 - (x + 5) = -415 - (15 - 415)

25 - (x + 5) = -415 - 400

25 - (x + 5) = -15

- (x + 5) = -15 - 25

- (x + 5) = -40

x + 5 = 40

x = 40 - 5

x = 35

c) 34 + (21 - x) = (3747 - 30) - 3746

34 + 21 - x = (3747 - 30) - 3746

55 - x = -29

x = 55 - (-29)

x = 84