Đáp án+Giải thích các bước giải:
Bài `2`:
`a) 175 . 16 + 84 . 175`
`=175. (16+84)`
`=175. 100`
`=17500`
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`b) 14. 2^3 - 2^3 . 3^2`
`= 8 (14 - 9)`
`= 8 . 5 = 40`
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`c) 640 : 160 [ 2^6: (37 -21)]`
`= 4 (64:16)`
`= 4.4=16`
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`d) 17.85 + 15.17 -120`
`= 17. (85+15) - 120`
`=17. 100 - 120`
`=1700-120= 1580`
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`e) 20 - [30- (5-1)^2]`
`=20 - (30 - 16)`
`=20 - 14 = 6`
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`f) 3^3 : 3^2 + 2^3. 2^2`
`= 3 + 2^5= 3+ 32=35`
------------------------------------------
`g) (39.42 -37.42) :42`
`= 42. (39 -37) :42`
`=42. 2:42=2`
--------------------------------------------
`h) (51.63-37.51):51`
`= 51(63-37):51`
`=51. 26:51`
`=26`
-----------------------------------------
`i) 11.25+95.11+98.51+69.89`
`=11.(25+95)+89(51+69)`
`=11. 120 + 89. 120`
`= 120(11+89)`
`=120.100=12000`
Bài `3`:
`a) 3x-35=40`
`=> 3x=75`
`=> x=25`
-----------------------
`b) 148: (x+2)=37`
`=> x+2= 4`
`=> x=2`
-------------------------
`c) 128 -(x+8).5=2^5:2^2`
`=> 218 - (x+8).5=8`
`=> 5(x+8)=210`
`=> x+8=42`
`=> x=34`
$@PIpimm~$ '-'
