2а(3а-b+4)=6a^2-2ab+8a
6a(a-x-c)+6x(a+x-c)-6c(a-x-c)=6a^2-6ax-6ac+6xa+6x^2-6xc-6ca+6cx-6c^2=6a^2+6x^2-6c^2-12ca
5(x-3)=14-2(7-2x)
5x-15=14-14+4x
5x-15=4х
х=15
2а(3а-b+4)=6a^2-2ab+8a
6a(a-x-c)+6x(a+x-c)-6c(a-x-c)=6a^2-6ax-6ac+6xa+6x^2-6xc-6ca+6cx-6c^2=6a^2+6x^2-6c^2-12ca
5(x-3)=14-2(7-2x)
5x-15=14-14+4x
5x-15=4х
х=15