Решите уравнения. 1) 1/2x=20 2) 3x-10=x+6 3) 5x-0,8=2x+8,2 4) 2x-(6x-57)=9 5)

Решим уравнения.
1) 1/2х = 20; х = 20 / 1/2 = 20 * 2 /1 = 40;
2) 3х - 10 = х + 6;
3х - х = 6 + 10;
2х = 16; х = 16 /2 = 8;
3) 5х - 0,8 = 2х + 8,2;
5х - 2х = 8,2 + 0,8;
3х = 9; х = 9 / 3 = 3;
4) 2х - (6х - 57)= 9;
2х - 6х + 57 = 9;
-4х = 9 - 57;
-4х = -48; х = (-48) / (-4) = 12;
5) 5х - (7х - 43) = 9;
5х - 7х + 43 = 9;
-2х = 9 - 43;
-2х = -34; х = (-34) / (-2) = 17;
6) 80 - 2 * (х - 40) = 4 * (х - 50);
80 - 2х + 80 = 4х -200;
80 + 80 +200 = 4х + 2х;
360 = 6х; х = 360 / 6 = 60;