§ 14: 14.14

14.14 Розв’яжіть рівняння

3(х+4)2 + 3(х-5)2 + 3(х+4)(х-5) = 3 •| (3х+4 – 3х-5);

(3(х+4)³ – (3(х-5)³ = 3(3х+4 – 3х-5); х + 4 – х + 5 = 3(3х+4 – 3х-5); 3(3х+4 – 3х-5) = 9; 3х+4 – 3х-5 = 3;

х + 4 – х + 5 – 33(х+4)(х-5)(3х+4 – 3х-5) = 27;

9 – 33х2-х-20 • 3 = 27; –93х2-х-20 = 18; 3х2-х-20 = –2;

х² – х – 20 = –8; х² – х – 12 = 0; х₁ = –3, х₂ = 4.