Pitomath
Anonymous
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- asked 4 months agoVotes
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a) −35x=1225;
b) 35x−34=−112;
c) 25+35:x=0,5;
d) 34−x−12=123;
e) 2215:13−5x=−225;
g) x2+19=53:3.
a) −35x=1225
x=1225:−35
x=1225.−53
x=−45
Vậy x=−45
b) 35x−34=−112
35x−34=−32
35x=−32+34
35x=−64+34
35x=−34
x=−34:35
x=−34.53
x=−54
Vậy x=−54
c) 25+35:x=0,5
25+35:x=12
35:x=12−25
35:x=510−410
35:x=110
x=35:110
x=35.10
x=6
Vậy x=6
d) 34−x−12=123
34−x−12=53
x−12=34−53
x=912−2012+12
x=−1112+612
x=−512
Vậy x=−512
e) 2215:13−5x=−225
3215:13−5x=−125
13−5x=3215:−125
13−5x=3215.5−12
13−5x=4.8−5.−3.−54.3
13−5x=−89
5x=13−−89
5x=39+89
5x=119
x=119:5
x=119.15
x=1145
Vậy x=1145
g) x2+19=53:3
x2=53.13−19
x2=59−19
x2=49
Trường hợp 1. x2=232
x=23
Trường hợp 2. x2=−232
x=−23
Vậy x = 23; x = −23.
Video giải bài tập Toán 7 Bài tập cuối chương 1
