Question

Помогите по алгебре сделать 19 и 20, пожалуйста дам 35 баллов

Answer 1

19)
1)
$4 {a}^{2} {c}^{3} - 4a {c}^{3} + {c}^{3} = {c}^{3} (4 {a}^{2} - 4a + 1) = {c}^{3} {(2a - 1)}^{2}$
2)
$12a {x}^{2} - 60ax + 75a = 3( 4{x}^{2} - 20x +25) = 3 {(2x - 5)}^{2}$
3)
$- 0.2 {y}^{2} + 1.2y - 1.8 = - 0.2( {y}^{2} - 6y + 9) = - 0.2 {(y - 3)}^{2}$
4)
$frac{1}{9} {a}^{2} + 1 frac{1}{3} a + 4 = frac{1}{9} {a}^{2} + frac{4}{3} a + 4 = {( frac{1}{3} a + 2)}^{2}$
20)
1)
$9 {a}^{2} - 25 {c}^{2} = (3a - 5c)(3a + 5c)$
2)
$0.81 {x}^{2} - 1.44 {y}^{2} = (0.9x - 1.2y)(0.9x + 1.2y)$
3)
$8 {a}^{3} - 27 = (2a - 3)(4 {a}^{2} + 6a + 9)$
4)
$0.001 {x}^{3} - 125 {a}^{3} = (0.1 x- 5a)(0.01 {x}^{2} + 0.5xa + 25 {a}^{2} )$