Вправи: 388

388. Розв’яжи рівняння.

a) 12x2- 9 + 2x+3 = 3x-3; 12+2x-3- 3(x+3)x2- 9 = 0; 12+2x-6-3x-9x2- 9 = 0;

-(x+3)x2- 9 = 0; x + 3 = 0, x = –3,

(x – 3)(x + 3)x ≠ 0; x ≠ 3, x ≠ –3; x = –9;

б) 2x+43-x + 1 = 5-xx+2; 2x+4x+2+ 3-xx+2- (5-x)(3-x)3-x(x+2) = 0;

2x2+ 4x+4x+8+3x+6- x2- 2x-15+5x+3x- x23-x(x+2) = 0; 17x-13-x(x+2) = 0;

17x – 1 = 0,

x ≠ 3, x ≠ –2; x = 117;

в) 2x2+ 8x-5x+3 – 2x = 1; 2x2+ 8x-5-2xx+3- (x+3)x+3 = 0;

2x2+ 8x-5- 2x2- 6x-x-3x+3 = 0; x-8x+3 = 0;

x – 8 = 0, x = 8,

x + 3 ≠ 0; x ≠ –3; x = 8;