Question

5 и 6 срочно пожалуйста!!"

Answer 1

5. (3x-1-2x)/6 =(5-x)/9
(x -1)*9 =(5 -x)*6
9x -9 =30 -6x
9x -6x =30 -9
3x =21
x =7

6. 2a(a+b-c)-2b(a-b-c)+ 2c(a-b+c) =2a²+2ab-2ac -2ab+2b²+2bc +2ac-2bc +2c² =2a²+2b²+2c² =2(a² +b²+c²)