Question

ПОМОГИТЕ РЕШИТЬ ПРИМЕРЫ КРОМЕ 1

ПОЙЖАЛУСТА ПОМОГИТЕ!!!!!!!!!!!!!!!!!!!!​

Answer 1

Пошаговое объяснение:

б)

$x {}^{2} + 2x + x + 2 = 4 {x}^{2} - 20x - \ 20x + 10 \ {x}^{2} + 3x + 2 = 4 {x}^{2} - 22x + 10 \ {x}^{2} + 3x + 2 - 4 {x}^{2} + 22x - 10 = x \ - 3 {x}^{2} + 25x - 8 = 0 \ - 3 {x}^{2} - 25x + 8 = 0 \ d = - 25 {}^{2} - 4 times 3 times 8 = 625 - 96 = 529 \ x(1.2) = frac{ - ( - 25) + - sqrt{529} }{2 times 3} = frac{25 + - 23}{6 } \ x(1) = frac{25 + 23}{6} = frac{48}{6} = 8 \ x(2) = frac{25 - 23}{6} = frac{2}{6} = frac{1}{3}$

в)

$frac{ {x}^{2} }{5 } - frac{2x}{3} = frac{x + 5}{6} ( times 30) \ 6 {x}^{2} - 20x = 5(x + 5) \ 6 {x}^{2} - 20x = 5x + 25 \ 6x {}^{2} - 20x - 5x - 25 = 0 \ 6x {}^{2} - 25 x - 25 = 0 \ d = - 25 {}^{2} - 4 times 6 times ( - 25) = - 25( - 25 - 4 times 6) = - 25( - 49) = 1225 \ x(1.2) = frac{( - 25) + - sqrt{1225} }{6 times 2} = frac{25 + - 35}{12} \ x(1) = frac{25 + 35}{12} = frac{60}{12} = 5 \ x(2) = frac{25 - 35}{12} = frac{ - 10}{12} = - frac{5}{6}$

г)

$frac{x {}^{2} }{6} - frac{2x}{3} = frac{3x - 10}{4} ( times 12) \ 2x {}^{2} - 8x = 3(3x - 10) \ 2 {x}^{2} - 8x = 9x - 30 \ 2 {x}^{2} - 8x - 9x + 30 = 0 \ 2 {x}^{2} - 17x + 30 = 0 \ d = - {17}^{2} - 4 times 2 times 30 = 289 - 240 = 49 \ x(1.2) = frac{ - ( - 17) + - sqrt{49} }{2 times 2} = frac{17 + - 7}{4} \ x(1) = frac{17 + 7}{4} = frac{24}{4} = 6 \ x(2) = frac{17 - 7}{4} = frac{10}{4} = frac{5}{2} = 2 frac{1}{2}$