Question

Помогите решить 102,желательно с объяснением,заранее спасибо.

Answer 1

решение на фото))))))

Answer 2

7) в конце первой строчки должно быть -3a^2, а не -3ab

Answer 3

и в 8 в начале -2x^3, а не 2х

Answer 4

$1) : : 2.4(5x - 10) - 5(x + 1) - 3(1 - 3x) = 2.4 times 5x - 2.4 times 10 - 5x - 5 - 3 + 3 times 3x = 12x - 24 - 5x - 5 - 3 + 9x = 16x - 32 = 16(x - 2)$
$2) : : - 2x(x + 4) + 5( {x}^{2} - 3x) = - 2x times x - 2x times 4 + 5 {x}^{2} - 5 times 3x = - 2 {x}^{2} - 8x + 5 {x}^{2} - 15x = 3 {x}^{2} - 23x$
$3) : : 3a(3a - {a}^{2} ) - 4a(2 {a}^{2} - 5a) = 3a times 3a - 3a times {a}^{2} - 4a times 2 {a}^{2} + 4a times 5a = 9 {a}^{2} - 3 {a}^{3} - 8 {a}^{3} + 20 {a}^{2} = 29 {a}^{2} - 11 {a}^{3}$
$4) : : 3m(n - 2m) - m(m + 4n) = 3mn - 3m times 2m - m times m - m times 4n = 3mn - 6 {m}^{2} - {m}^{2} - 4mn = - 7 {m}^{2} - mn$
$5) : : 0.3 {x}^{2} ( {x}^{2} - 3x + 2) - 0.6x(2 {x}^{3} + 6 {x}^{2} - 4x) = 0.3 {x}^{2} times {x}^{2} - 0.3 {x}^{2} times 3x + 0.3 {x}^{2} times 2 - 0.6x times 2 {x}^{3} - 0.6x times 6 {x}^{2} + 0.6x times 4x = 0.3 {x}^{4} - 0.9 {x}^{3} + 0.6 {x}^{2} - 1.2 {x}^{4} - 3.6 {x}^{3} + 2.4 {x}^{2} = - 0.9 {x}^{4} - 4.5 {x}^{3} + 3 {x}^{2}$
$6) : : 4x(7y - 3 {x}^{2} ) - 3y(x - {y}^{2} ) = 4x times 7y - 4x times 3 {x}^{2} - 3yx + 3y times {y}^{2} = 28xy - 12 {x}^{3} - 3xy + 3 {y}^{3} = - 12 {x}^{3} + 25xy + 3 {y}^{3}$
$7) : : 5a(3 {a}^{2} - 2b) + 17b(2a + b) - 3a( - 4b + a) = 5a times 3 {a}^{2} - 5a times 2b + 17b times 2a + 17 {b}^{2} + 3a times 4b - 3 {a}^{2} = 15 {a}^{3} - 10ab + 34ab + 17 {b}^{2} + 12ab - 3 {a}^{2} = 15 {a}^{3} + 36ab + 17 {b}^{2} - 3 {a}^{2}$
$8) : : 2 {x}^{3} (3x - 1) - 4x( {x}^{3} - 2 {x}^{2} + 3x) - 5x - 2 {x}^{4} = 2 {x}^{3} times 3x - 2 {x}^{3} - 4x times {x}^{3} + 4x times 2 {x}^{2} - 4x times 3x - 5x - 2 {x}^{4} = 6 {x}^{4} - 2 {x}^{3} - 4 {x}^{4} + 8 {x}^{3} - 12 {x}^{2} - 5x - 2 {x}^{4} = 6 {x}^{3} - 12 {x}^{2} - 5x$

Answer 5

Спасибо)