Question

Срочно! Помогите пожалуйста!

Answer 1

1.

$(a+\frac{1}{a}+2)*\frac{1}{a+1}, a=2\\(2+\frac{1}{2} +2)*\frac{1}{2+1}= (2+0,5+2)*\frac{1}{3} =4,5*\frac{1}{3}=\frac{4,5}{3}=1,5$

2.

$(2-c)^2-c(c+4)=4-4c+c^2-c^2-4c=4-4c-4c=4-8c, c=0,5\\4-8*0,5=4-4=0$

3.

$\frac{16}{4a-a^2}-\frac{4}{a}=\frac{16}{a(4-a)}-\frac{4}{a}=\frac{16-4(4-a)}{a(4-a)}=\frac{16-16+4a}{a(4-a)}=\frac{4a}{a(4-a)}=\frac{4}{4-a} , a=-12\\\frac{4}{4-(-12)} =\frac{4}{16} =\frac{1}{4} =0,25$

4.

$(a-3)^2-a(5a-6)=a^2-6a+9-5a^2+6a=-4a^2+9, a=-\frac{1}{2} \\-4*(-\frac{1}{2})^2+9=8$

5.

$\frac{4b}{a-b}*\frac{a^2-ab}{8b}=\frac{1}{a-b}*\frac{a(a-b)}{2}=\frac{a}{2}, a=19, b=8,2\\\frac{19}{2}=4,5$