Вправи: 280

280. Розв’яжи рівняння.

a) (2x – 8) – (5x + 6) = 4;

2x – 8 – 5x – 6 = 4;

–3x = 8 + 6 + 4;

–3x = 18|: (–3);

x = –6.

б) 16y – (3 – 2y) + (7y + 1) = 48;

16y – 3 + 2y + 7y + 1 = 48;

25y = 48 + 3 – 1;

25y = 50|: 25;

y = 2.

в) 24 – (x² + 8x – 17) = 5 – 5x – x²;

24 – x² – 8x + 17 = 5 – 5x – x²;

–8x + 5x = 5 – 24 – 17;

–3x = –36|: (–3);

x = 12.

г) (x – 2x⁴ + 7) – (3x + 3 – 5x⁴) = 6 + 3x⁴.

x – 2x⁴ + 7 – 3x – 3 + 5x⁴ = 6 + 3x⁴;

3x⁴ – 2x = 3x⁴ – 7 + 3 + 6;

–2x = 2|: (–2);

x = –1.