1) (2x-5) (x+2)=18 2) (4x-3)^2+(3x-1)(3x+1)=9 3) (x+3)^2-(2x-1)^2=16 4) (x-6)^2-2x(x+3)=30-12x 5) (x+7) (x-8)-(4x+1) (x-2)= -21x 6) (2x-1) (2x+1)-x(1-x)=2x(x+1) Помогите, кто знает! Фигню не пишите! Плиз....

1) 2x²- x - 10 = 18 2x² - x - 28 = 0 D = b² - 4ac = 1 + 224 = 225 = 15² x1 = ( 1 + 15) / 4 = 4 x2 = ( 1 - 15) / 4 = - 3,5 2) 16x² - 24x + 9 + 9x² - 1 = 9 25x² - 24x - 1 = 0 D = b² - 4ac = 576 + 100 =676 = 26² x1 = ( 24 + 26) / 50 = 1 x2 = ( 24 - 26) / 50 = - 0,04 3) x² + 6x + 9 - ( 4x² - 4x + 1) = 16 x² + 6x + 9 - 4x² + 4x - 1 - 16 = 0 - 3x² + 10x - 8 = 0 3x² - 10x + 8 =0 D =b ² -4ac = 100 - 96 = 4 = 2² x1 = ( 10 + 2) / 6= 2 x2 = ( 10 - 2) / 6 = 8/6 = 4/3 = 1 1/3 4) x² - 12x + 36 - 2x² - 6x = 30 - 12x - x² - 6x + 6 =0 x² + 6x - 6 = 0 D = 36 + 24 = 60 x1 = ( - 6 + √60) / 2 x2 = ( - 6 - √60) / 2 5) x²- x - 56 - ( 4x²- 7x - 2) = - 21x x² - x - 56 - 4x² + 7x + 2 + 21x =0 - 3x² + 27x - 54 = 0 x² - 9x + 18 =0 D = 81 - 72 = 9 = 3² x1 = ( 9 + 3) / 2 = 6 x2 =( 9 - 3) / 2 = 3 6) 4x² - 1 - x + x² = 2x² + 2x 5x² -2x² - x - 2x - 1 = 0 3x² - 3x - 1 = 0 D = 9 + 12 = 21 x1 = ( 3 + √21) / 6 x2 =( 3 - √21) / 6