4.250 : (x−8) = 25;
5.400−2(x+ 25) = 100;
6.3x+ 7 = 22.10;
7.2x+ 3 = 54: 52;
8.18 + 3(x−2) = 8.(23−5);
9.2.(32−2x+1) + 10 = 42;
10.3.2x+ 2x+3= 44;11.6...(x+ 2);
12.x∈N,x...12, x...15, x...18, và x <900;
13.(x−1)+(x−3)+...+(x−100) = 5550;
14.(x+ 2) + (x+ 4) +...+ (x+ 50) = 600.
help mình với><! Ai đúng mik tick nha
4.250 : (x−8) = 25
<=> x - 8 = 250 :25
<=> x- 8 = 10
<=> x = 10 + 8
<=> x = 18
Vậy x= 18.
5.400−2(x+ 25) = 100
<=> 400 - 2x + 50 = 100
<= > 400 - 2x = 100-50
<=> 400 - 2x = 50
<=> 2x = 400 - 50
<=> 2x =350
<=> x = 350: 2
<=> x = 175.
Vậy x = 175
6.3x+ 7 = 22.10
<=> 3x + 7= 220
<=> 3x = 220 - 7
<=> 3x = 213
<=> x = 213 :3
<=> x = 71
Vậy x = 71.
7.2x+ 3 = 54: 52
<=> 2x +3 = 27/26
<=> 2x = 27/26 - 3
<=> 2x = - 51/26
<=> x = -51/26 :2
<=> x = - 51/26
Vậy x= -51/26