1) a)a^2 - 4;
b)9-y^2;
2) a)9b^2-1;
b)25b^2-36
A) 36x²-1 -36x²-8x = -1
-1 -8x= -1
8x= -1+1
8x=0
x=0
b) 8a -9a²= -40 +36 -9a²
8a -9a² +9a² = -4
8a= -4
a= -4/8= -0.5
X^3-4x^2-7x+28=0
x^2(x-4)-7(x-4)=0
(x^2-7)(x-4)=0
x^2-7=0 или x-4=0
x=√7 x=4
x=-√7
Ответ:<span>x=√7
</span><span>x=-√7
</span><span>x=4</span>