1 1/2 =3/2
22.5 =225/10 =45/2
1 2/3 =5/3
1) 3/2 : 45/2 * 5/3 =3/2 *2/45 *5/3 =(3*2*5) /(2*45*3) =5/45 =1/9
2) 6 -1/9 =5 9/9 -1/9 =5 8/9 =53/9
3) 53/9 - (-2/3) =53/9 +2/3 =(53 +2*9)/9 =(53 +18)/9 =71/9 =7 8/9
А) 2x^2-18=0
2x^2=18
x^2=18/2=9
x=3 ; -3
Б) 5x^2+15x=0
x(5x+15)=0
x1=0
5x+15=0
5x=-15
X2=-3
В) x^2+5=0
x^2=-5
Корней нет
Г) 6x^2-12=0
6x^2=12
x^2=2
x=√2; -√2
Д) 3x^2+12x=0
x(3x+12)=0
x1=0
3x+12=0
3x=-12
x=-4
Е) 7+x^2=0
x^2=-7
Корнет нет
f(x) = (x² - 2x - 3)²
f'(x) = 2(x² - 2x - 3)(2x - 2) = 4(x² - 2x - 3)(x - 1) = 4(x - 3)(x + 1)(x - 1)
f'(x) = 0 => 4(x - 3)(x + 1)(x - 1) = 0
x - 3 = 0 => x = 3
x + 1 = 0 => x = -1
x - 1 = 0 => x = 1
Ответ: x = 3, x = 1, x = -1.