Вот, тут всё есть . . . . . . . . . . . . . .. . . .
1. <span>((a+b)-(a-b))*((a+b)+(a-b))*(1/a+1/b) = (a+b-a+b)*(a+b+a-b)*(1/a+1/b) = 2a*2b*(a+b)/ab = 4a+4b = 4(a+b)</span>
2. (1,8<span>·3</span>)(10-3<span>·105</span>)=5,4
3. -164
4. 3,3
5. 6
6. А
7. Б
20х-4(2х-1)+5(1-2х)=20х-8х+4+5-10х=2х+9=-6+9=3
A∩B={5;7}
A∪B={1;2;3;4;5;7}
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Log0,5 (x^2-3x)=-2
ОДЗ: x^2-3x>0 или
x<0 и x>3
x^2-3x = 0,5^(-2)
x^2-3x -4 = 0
x1 = 4
x = -1
log2 Vх -log2 1/x =3
ОДЗ: x>0
log2 {Vx\(1\x)} = 3
xVx = 2^3
(x^(3\2))^2 = 2^6
x^3 = 2^6
<span>x = 2^2 = 4</span>