X=2, y=1.
3x+5y=11, 5x=2(y+4)
y=11/5(дробь)-3x/5 (дробь);
y=5x/2 (дробь)-4
1)(b-2a)^2-(2b+a)(2b-a)=b^2-4ab+4a^2-(4b^2-a^2)=
=b^2-4ab+4a^2-4b^2+a^2=3a^2-3b^2-4ab
2)<span>4p (p-5)-(2p-3)^2 =4p^2-20p-(4p^2-12p+9)=
4p^2-20p-4p^2+12p-9=-8p-9
-8*1,25-9=-12+9=-3
3)</span>
<span>А)(а-8)(а+8)=a^2-64
Б)(х^2+4)(х^2-4)=x^4-16
В)(0,2m+10n)(0,2m-10n)=0,04m^2-100n^2
Г)(3b^2+5a)(5a-3b^3)</span>
=25a^2-9b^6
4 - lg ^2(x) =3 * lg(х)
пусть lg(х) = y
4 - y^2 = 3y
y^2 + 3y - 4 = 0
По теореме Виетта: y1 + y2 = -3 и y1 * y2 = -4
y1 = 1 или y2 = -4 =>
lg(х) = 1 или lg(х) = -4 =>
<span>x = 10 или x = 10^(-4) = 0.0001</span>
Решение
log₂² x - 4log₂ x + 3 = 0
ОДЗ: x > 0
log₂ x = t
t² - 4t + 3 = 0
t₁ = 1
t₂ = 3
1) log₂ x = 1
x = 2¹
x₁ = 2
2) log₂ x = 3
x = 2³
x₂ = 8