Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!!!!
СРОЧНО!!!!!!!! ​

Answer 1

Ответ:

$a)\ \ a=-3,6\ ,\ b=-7,6\\\\\Big(\dfrac{(a+b)^2}{a}-4b\Big)\cdot \dfrac{3a}{8}=\dfrac{a^2+2ab+b^2-4ab}{a}\cdot \dfrac{3a}{8}=\dfrac{a^2-2ab+b^2}{a}\cdot \dfrac{3a}{8}=\\\\\\=\dfrac{(a-b)^2}{a}\cdot \dfrac{3a}{8}=\dfrac{(a-b)^2\cdot 3}{8}=\dfrac{(-3,6+7,6)^2\cdot 3}{8}=\dfrac{4^2\cdot 3}{8}=\dfrac{16\cdot 3}{8}=\\\\\\=2\cdot 3=6$

$b)\ \ a=12\dfrac{4}{9}\ \ ,\ \ b=3\dfrac{5}{9}\\\\\dfrac{a^2-b^2}{4ab}:\Big(\dfrac{2}{b}-\dfrac{2}{a}\Big)=\dfrac{(a-b)(a+b)}{4ab}:\dfrac{2a-2b}{ab}=\dfrac{(a-b)(a+b)}{4ab}\cdot \dfrac{ab}{2(a-b)}=\\\\\\=\dfrac{(a+b)}{4\cdot 2}=\dfrac{12\dfrac{4}{9}+3\dfrac{5}{9}}{8}=\dfrac{(12+3)+(\dfrac{4}{9}+\dfrac{5}{9})}{8}=\dfrac{15+\dfrac{9}{9}}{8}=\dfrac{15+1}{8}=\dfrac{16}{8}=2$

$c)\ \ a=1\dfrac{5}{11}\ ,\ b=3\dfrac{6}{11}\\\\\Big(\dfrac{(a-b)^2}{2b}+2a\Big):\dfrac{1}{4b}=\dfrac{a^2-2ab+b^2+4ab}{2b}\cdot 4b=\dfrac{a^2+2ab+b^2}{2b} \cdot 4b=\\\\\\=(a+b)^2\cdot 2=\Big(1\dfrac{5}{11}+3\dfrac{6}{11}\Big)^2\cdot 2=\Big(1+3+\dfrac{11}{11}\Big)^2\cdot 2=(1+3+1)^2\cdot 2=\\\\\\=5^2\cdot 2=25\cdot 2=50$

$d)\ \ a=2\dfrac{2}{5}\ \ ,\ \ b=2\dfrac{3}{5}\\\\\dfrac{a^2-25b^2}{7ab}:\Big(\dfrac{1}{5b}-\dfrac{1}{a}\Big)=\dfrac{(a-5b)(a+5b)}{7ab}:\dfrac{a-5b}{5ab}=\dfrac{(a-5b)(a+5b)}{7ab}\cdot \dfrac{5ab}{a-5b}=\\\\\\=\dfrac{(a+5b)\cdot 5}{7}=\dfrac{(2\dfrac{2}{5}+2\dfrac{3}{5})\cdot 5}{7}=\dfrac{(4+\dfrac{5}{5})\cdot 5}{7} =\dfrac{5\cdot 5}{7}=\dfrac{25}{7}=3\dfrac{4}{7}$