Вероятность купить бракованный 25/5000=0,005
не бракованный 1-0,005=0,995 или 99,5%
(y-1)^2+ 2y-2=y^2-2y+1+2y-2=y^2-1=(y+1)(y-1)
<span> 2x+2 = 5</span>
2x=3
x=3/2
4z^3-z=z(4z^2-z)
<span> z-2z=0
-z=0
z=0
</span>
х+6+х+6+х+х=80
4х+12=80
4х=68
х=68:4
х=17см - одна сторона
х+6=17+6=23 см - вторая сторона
17*23=391см - площадь прямоугольника
1.
5²¹ * 5 ⁻²³= 5²¹⁺⁽⁻²³⁾ = 5⁻² = 1/5² = 1/25 = 0.04
3⁻⁸ / 3⁻⁹ = 3⁻⁸⁻⁽⁻⁹⁾ = 3⁻⁸⁺⁹ = 3¹ = 3
(2²)⁻³ = 2²*⁽⁻³⁾ = 2⁻⁶ = 1/2⁶ = 1/64
2.
(a⁻³)⁵ * a¹⁸ = a⁻³*⁵ ⁺¹⁸ = a⁻¹⁵⁺¹⁸ = a³
2.4x⁻⁸y⁵ * 5x⁹y⁻⁷ = (2.4 * 5) * x⁻⁸⁺⁹ *y⁵⁺⁽⁻⁷⁾ = 12x¹ y⁻² = 12xy⁻²
3.
(1/4 * x⁻²y⁻³) ⁻² = (2⁻² x⁻²y⁻³)⁻² = 2⁴x⁴y⁶ = 16x⁴y⁶
(5x⁻¹ /3y⁻²) * 15x³y = (5* x⁻¹ * (3 * 5 ) * x³ *y¹ ) / (3y⁻²) =
= (5² * 3¹ * x⁻¹⁺³ y¹)/(3¹*y⁻²) = 5² * 3¹⁻¹ *x² * y¹⁻⁽⁻²⁾ = 25x²y³
4.
(4 ⁻⁶ * 16)/(64⁻⁵) = (4⁻⁶ * 4²) / (4³)⁻⁵ = 4⁻⁶⁺²⁻⁽⁻¹⁵⁾ = 4⁻⁴⁺¹⁵ = 4¹¹
5.
(2.5 * 10⁷) * (6.2 * 10⁻¹⁰) = (2.5*6.2) * 10⁷⁺⁽⁻¹⁰⁾ = 15.5 * 10⁻³
6.
(x ⁻¹ - y )(x - y ⁻¹)⁻¹ = (1/x - y )(x - 1/y) ⁻¹ =
= ( (1-xy)/x ) * ( (xy - 1)/y ) ⁻¹ =
= (1-xy)/x * y/(xy - 1) =
= (1 - xy)/x * ( - y/(1 -xy) ) =
= - y/x = - yx⁻¹
Думаю, достаточно...