Вправи: 782

782. Розв’яжіть рівняння:

а) 200(x - 5) = 100(x + 1) + 500; 200x - 1000 = 100x+ 100 + 500;

200x - 100x = 600 + 1000; 100x = 1600; x = 16;

б) 350x + 250(5x - 4) - 800 = 0; 350x + 1250x - 1000 - 800 = 0;

1600x = 1800; x = 1800 : 1600; х = 1,125;

в) 130(2x - 5) + 730 = 1730x; 2x - 5 + 7 = 17x; 2x - 17x = -2; -15x = -2;

x = 215;

г) (1 - 12 + 13 - 16)(x + 1) = 112; 23(x + 1) = 112; x + 1 = 112 : 23; x + 1 =

= 18; x = 18 - 1; x = -78.