выполните действия; (-7x-1)**;(a**-2b)**;(8x+x***)**;(4a-b**)**;(x****-9x)** раскройте скобки     (3а-в)**-(3а+в)**;(a+(b-c))**; (2x+y)**-(2x-y)**;(c-(a+b))**

(-7x-1)**=49x**+14x+1;

(a**-2b)**=a****-4a**b+4b**;

(8x+x***)**=64x**+16x***8+x******;

(4a-b**)**=16a**-8ab**+b****;

(x****-9x)**=x******-18x*****+81x***

 (3а-в)**-(3а+в)**=9a**-6ab+b**-9a**-6ab-b**=-12ab;

(a+(b-c))**=a**+2a(b-c)+(b-c)**=a**+2ab-2ac+b**-2bc+c**; 

(2x+y)**-(2x-y)**=4x**+4xy+y**-4x**+4xy-y**=8xy;

(c-(a+b))**=c**-2c(a+b)+(a+b)**=c**-2ac-2bc+a**+2ab+b**