Question

Помогите срочно надооооо
Помогите

Answer 1

6) $\frac{2-a}{a+2}+ \frac{2a}{2-a}+ \frac{4 a^{2} }{ a^{2} -4} = \frac{2-a}{a+2}- \frac{2a}{a-2} + \frac{4 a^{2} }{(a-2)(a+2)}= \frac{2a-4- a ^{2} +2a-2 a^{2}-4a+4 a^{2} }{(a-2)(a+2)}$$= \frac{ a^{2}-4 }{ a^{2} -4} =1$

7) $(x+3+ \frac{18}{x-3} )* \frac{2 x^{2} -12x+18}{ x^{2} +9} = \frac{ x^{2} -9+18}{x-3}* \frac{2( x^{2} -6x+9)}{ x^{2} +9}= \frac{ x^{2} +9}{x-3} * \frac{2(x-3) ^{2} }{ x^{2} +9}=$$x-3$

8) Умножим почленно на 12

$\frac{(x-3) ^{2} }{12}*12- \frac{2 x^{2} +5}{4}*12+ \frac{1,25 x^{2} -1}{3}*12= \frac{2}{3}*12 \\\\(x-3) ^{2}-3(2 x^{2} +5)+4(1,25 x^{2} -1)=8$

x² - 6x + 9 - 6x² - 15 + 5x² - 4 - 8 = 0

- 6x = 18
x = - 3

Answer 2

6
(2-a)/(a+2)+2a/(2-a)+4a²/(a-2)(a+2)=(2-a)/(a+2)+2a/(2-a)-4a²/(2-a)(a+2)=
[(2-a)²+2a(a+2)-4a²]/(4-a²)=(4-4a+a²+2a²+4a-4a²)/(4-a²)=
=(-a²+4)/(4-a²)=1
7
1)(x+3)+18/(x-3)=(x²-9+18)/(x-3)=(x²+9)/(x-3)
2)(x²+9)/(x-3)*2(x²-6x+9)/(x²+9)=2(x-3)²/x-3)=2(x-3)=2x-6
8
Домножим на 12
(x-3)²-3(2x²+5)+4(1,25x²-1)=4*2
x²-6x+9-6x²-15+5x²-4=8
-6x=8+10
-6x=18
x=-3