Помогите 1) x(0.5+0.3)-(7-4x)=3x-0.4 2) 4-3(0.5-7x)=21 3) 0.4(x-3)=7(5-x)

Question

Помогите
1) x(0.5+0.3)-(7-4x)=3x-0.4
2) 4-3(0.5-7x)=21
3) 0.4(x-3)=7(5-x)

Answer 1

1) х*0,8-7+4х=3х-0,4
0,8х-7+4х=3х-0,4
4,8х-3х= -0,4+7
1,8х=6,6
х=11/3=3 2/3

Comments

2) 4-1,5+21х=21; 2,5+21х=21; 21х=21-2,5; 21х=18,5; х=18,5:21; х=37/2*1/21=37/42

---

3)0,4х-1,2=35-7х; 0,4х+7х=35+1,2; 7,4х=36,2; х=181/37=4 33/37