Question

1,2,4 Очеееень срочно

Answer 1

$1. \frac{7}{3} \times \frac{6}{7} - \frac{9}{4} \times \frac{4}{23} =2- \frac{9}{23} =1 \frac{14}{23}$

$2. \sqrt{2^2+( \sqrt{7})^2+2*2* \sqrt{7} } - \sqrt{1^2+( \sqrt{3})^2-2*1* \sqrt{3} } =\\\\= \sqrt{(2+ \sqrt{7})^2 }- \sqrt{( \sqrt{3} -1)^2} =2+ \sqrt{7} - \sqrt{3} +1=\\\\=3+ \sqrt{7} - \sqrt{3}$

$4.5x-9+5x-7=4\\\\ 10x=20\\\\ x=2$