1) Tính a) 29. 87+29.14-29 b) 249 - 25.2 mũ 3+ 2mũ24: 2 mũ 22. 3 mũ 2 c) 321-21.[(2.3 mũ 3+ 4 mũ 4:32)-52] d)204.42+204.33+204.25 e) 4 mũ 13: 4 mũ11- 3 mũ 2.3-2017 mũ 0 G) [ 155-15(2.5 mũ 2-3.4 mũ 2)] : (12-7) mũ 3 H) 17.81+17.35+116.83 i)5 mũ 15: 5 mũ 10-25.2 mũ 2 K)125-[68+8.(37-35) mũ 2] : 7 2) tìm x biết a)2x+10=210 B)5.(3x+2)=2 mũ 2. 5 mũ 2 c)2x-15=75 d)4 mũ 2.10:2(x-15)=4 e)4(x-3)=7 mũ 2- 1 mũ 30

Bài 1:

`a)` `29*87+29*14-29`

`=29*(87+14-1)`

`=29*100`

`=2900`

-

`b)` `249-25*2^3+2^24:2^22*3^2`

`=249-25*8+2^2*3^2`

`=249-200+4*9`

`=49+36`

`=85`

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`c)` `321-21*[(2*3^3+4^4:32)-52]`

`=321-21*(2*27+2^8:2^5-52)`

`=321-21*(54+8-52)`

`=321-21*10`

`=321-210`

`=111`

-

`d)` `204*42+204*33+204*25`

`=204*(42+33+25)`

`=204*100`

`=20400`

-

`e)` `4^13:4^11-3^2*3-2017^0`

`=4^2-3^3-1`

`=16-27-1`

`=-12`

-

`g)` `[155-15*(2*5^2-3*4^2)]:(12-7)^3`

`=[155-15*(50-48)]:5^3`

`=(155-15*2):5^3`

`=125:125`

`=1`

-

`h)` `17*81+17*35+116*83`

`=17*(81+35)+116*83`

`=17*116+116*83`

`=116*(17+83)`

`=116*100`

`=11600`

-

`i)` `5^15:5^10-25*2^2`

`=5^5-25*4`

`=3125-100`

`=3025`

-

`k)` `125-[68+8*(37-35)^2]:7`

`=125-(68+8*4):7`

`=125-100/7`

`=(875-100)/7`

`=775/7`

-

Bài 2:

`a)` `2x+10=210`

`2x=210-10`

`2x=200`

`x=100`

Vậy `x=100`

-

`b)` `5*(3x+2)=2^2*5^2`

`3x+2=(2^2*5^2)/5`

`3x+2=4*5`

`3x=20-2`

`3x=18`

`x=6`

Vậy `x=6`

-

`c)` `2x-15=75`

`2x=75+15`

`2x=90`

`x=45`

Vậy `x=45`

-

`d)` `4^2*10:2*(x-15)=4`

`16*10:2*(x-15)=4`

`80*(x-15)=4`

`x-15=4/80`

`x=1/20+15`

`x=301/20`

Vậy `x=301/20`

-

`e)` `4*(x-3)=7^2-1^30`

`4*(x-3)=49-1`

`4*(x-3)=48`

`x-3=12`

`x=12+3`

`x=15`

Vậy `x=15`