Question

Упростите выражение:
1) (2x − 1)(4x² + 2x + 1) - 4x(2x² - 3);
2) m(m+2)(m–2)–(m–3)(m²+3m+9)
за спам бан​

Answer 1

формулы:

(a-b)(a²+ab+b²)=a³-b³

a²-b²=(a-b)(a+b)

1)

(2x − 1)(4x² + 2x + 1)-4x(2x² - 3)=

=(2x)³-1³-8x³+12x=

=8x³-1-8x³+12x=

=12x-1

2)

m(m+2)(m–2)–(m–3)(m²+3m+9)=

=m(m²-2²)-m³-3³=

=m(m²-4)-m³-27=

=m³-4m-m³-27=

= -4m+27

Answer 2

$\displaystyle\bf\\1)\\\\(2x-1)(4x^{2} +2x+1)-4x(2x^{2} -3)=(2x)^{3} -1^{3} -8x^{3} +12x=\\\\=8x^{3} -1-8x^{3} +12x=12x-1\\\\2)\\\\m(m+2)(m-2)-(m-3)(m^{2} +3m+9)=\\\\=m\cdot(m^{2}-4)-(m^{3} -3^{3} )=m^{3} -4m-m^{3}+27=\\\\=27-4m$