Вправи: 1296

1296. Розв’яжіть рівняння:

1) 4 + 9х – 1 = 19 + 11х – 3х;

9х – 11х + 3х = 19 + 1 – 4;

х = 16.

2) –5(у – 7) = 30 – (2у + 1);

–5у + 35 = 30 – 2у – 1;

–5у + 2у = 30 – 1 – 35;

–3у = –6;

у = 2.

3) –4,5(х + 1) = –12 – 5(х – 2);

–4,5х – 4,5 = –12 – 5х + 10;

–4,5х + 5х = 10 + 4,5 – 12;

0,5х = 2,5;

х = 5.

4) 3(2,4t – 3,5) + 6 = 9,7t – 3;

7,2t – 10,5 + 6 = 9,7t – 3;

7,2t – 9,7t = 10,5 – 3 – 6;

–2,5t = 1,5;

t = –0,6.