Question

a)
(2a+3b)(4a²-6ab+9b²)
b)
(5-2y)(25x²+10xy+4y²)
c)
(m²-m+2)(3m²-2)
d)
(5-2a+a²)(4a²-3a-1)

Answer 1

a) (2a+3b)(4a²-6ab+9b²)=(2a)³+(3b)³=8a³+27b³

b) (5x-2y)(25x²+10xy+4y²)=(5x)³-(2y)³=125x³-8y³

c) (m²-m+2)(3m²-2)=3m⁴+4m³-3m³+2m-4

d) (5-2a+a²)(4a²-3a-1)=4a⁴-11a³+25a²-13a-5

Answer 2

$a)8 {a}^{3} - 12 {a}^{2} b + 18 {ab}^{2} + 12 {a}^{2} b \\ - 18 {ab}^{2} + 27 {b}^{3} = 8 {a}^{3}$+27b^3
$b)125 {x}^{2} + 50xy + 20 {y}^{2} - 50 {x}^{2} y \\ - 20 {xy}^{2} - 8 {y}^{3}$
$c)3 {m}^{4} - 2 {m}^{2} - {3m}^{3} + 2m \\ + {6m}^{2} - 4 = 3 {m}^{4} + {4m}^{2} - {3m}^{3} \\ + 2m$
$d)20 {a}^{2} - 15a - 5 - 8 {a}^{3} + 6 {a}^{2} \\ + 2a + 4 {a}^{4} - 3 {a}^{3} - {a}^{2} = \\ 25{a}^{2} - 13a - 5 - 11 {a}^{3} + 4 {a}^{4}$