Question

решите уравнения 1) 7x=20 (2)1,5x=90 (3)3x+15=45 (4)13a-5=3x-25(5)3-5(x+1)=6-4X

Answer 1

1) 7x = 20;
    x = 20 / 7;
    x = $2 frac{6}{7}$;
2) 1,5x = 90;
    x = 90 / 1,5;
    x = 6;
3) 3x + 15 = 45;
    3x = 30;
    x = 10;
4) 13x - 5 = 3x - 25;
    13x - 3x = -25 + 5;
    10x = -20;
     x = -2;
5) 3 - 5(x + 1) = 6 - 4x;
    3 - 5x + 1 = 6 - 4x;
    -5x + 4x = 6 - 3 + 1;
    -x = 4;
    x = -4.