<span> куб разности <span><span>(<span>a-b</span>)</span>^3</span> = <span><span><span><span>a^3-</span><span><span>3<span>a^2</span></span>b</span></span>+<span><span>3a</span><span>b^2-</span></span></span><span>b^3</span></span> </span><span>.
(a-1)^3= a^3-3a^2+3a-1</span>
<span>4*(4^-x)-9*(2^-x)+2>0
</span>4*(2^-x) ² <span>-9*(2^-x) +2>0
</span>замена (2^-x)= а ОДЗ а>0
4a² <span>-9a +2>0
D=81-32=49
a</span>₁<span>=(9+7)/8=2 </span>2⁻ˣ =2 x₁= -1<span>
a</span>₂<span>=(9-7)/8= 1/4= 2</span>⁻² 2⁻ˣ = 2⁻² x₂= 2
+ - +
____________-1 ____ 2_____________
x∈(-∞;-1)∪(2;+∞)
<span>(2a+1)^2-(a-9)^2=(2a+1-a+9)(2a+1+a-9)= (a+10)(3a-8)</span>