Question

Помогите, пожалуйста, 1)преобразовать в многочлен выражение, 2)упростить выражение, 3)упростить выражение и найти его значение

Answer 1

$1)(4 {m}^{2} + 6)(4m - 6) = \ 16 {m}^{3} - 24 {m}^{2} + 24m - 36$
$(3a - b)(2a - 7b) = {6a}^{2} - 21ab \ - 2ab + 7 {b}^{2} = {6a}^{2} - 23ab + {7b}^{2}$
$( {2x}^{2} - x)( {8x}^{2} - 2x) = \ {16x}^{4} - 4 {x}^{3} - {8x}^{3} + {2x}^{2} = \ 16 {x}^{4} - {12x}^{3} + {2x}^{2}$
$(a - 4b)( {a}^{2} + 3ab - 6 {b}^{2} ) = \ {a}^{3} + 3 {a}^{2} b - 6 {ab}^{2} - 4 {a}^{2} b - 12 {ab}^{2} \ + 24 {b}^{3} = {a}^{3} - {a}^{2} b - 18 {ab}^{2} + 24 {b}^{3}$
$a(4a - 5)(2a + 3) = \ a( {8a}^{2} + 12a - 10a - 15) = \ {8a}^{3} + {12a}^{2} - 10 {a}^{2} - 15a = \ {8a}^{3} + {2a}^{2} - 15a$
$- {5c}^{2} (6 - 4c)( {2c}^{2} + 7c) = \ - 5 {c}^{2} (12 {c}^{2} - 42c - 8 {c}^{3} - 21 {c}^{2} ) = \ - {5c}^{2} ( - {9c}^{2} - 42c - 8 {c}^{3} ) =$
$= 45 {c}^{4} + 210 {c}^{3} + 40 {c}^{5}$
2.
$1) {x}^{2} - 11x - 2x + 22 - 8x + {6x}^{2} \ = {7x}^{2} - 21x + 22$
$2) {a}^{2} - 3a + 6a - 18 + {a}^{2} + 5a \ - 4a - 20 = 2 {a}^{2} + 4a - 38$
3)
${x}^{2} + 5x - 2x - 10 - ( {x}^{2} - 4x \ + 3x - 12) = \ {x}^{2} + 3x - 10 - ( {x}^{2} - x - 12) = \ {x}^{2} + 3x - 10 - {x}^{2} + x + 12 =$
$= 4x + 2 \ 4 times ( - 4.5) + 2 = \ - 18 + 2 = - 16$