Question

A)(5а-в)(5а+в)
Б)(x-7)^2-3x(x+5)

Разложить на:
А)4х+4у-z(x+y);
Б)m^3-m^2-9m+9;
В)4t^2(t-5)^2

Answer 1

$(5a-b)(5a+b)=(5a)^2-(b)^2=5^2a^2-b^2=25a^2-b^2$


$(x-7)^2-3x(x+5)=(x^2-2*7*x+7^2)-3x*x-3x*5=$
$=x^2-14x+49-3x^2-15x=x^2-3x^2-14x-15x+49=$
$=-2x^2-29x+49$

a) $<span>4x+4y-z(x+y)=</span>4(x+y)-z(x+y)=(x+y)(4-z)$
b) $m^3-m^2-9m+9=m^2(m-1)-9(m-1)=$
$=(m-1)(m-3)(m+3)$
c) $4t^2-(t-5)^2=(2t)^2-(t-5)^2=[(2t)-(t-5)]*[(2t)+(t-5)]=$
$=[t+5]*[3t-5]$