Question

Помогите решить 2x-3(7-2x)=3, 30-x=3(20-x)
-y+8-14y=23

Answer 1

$2x - 3(7 - 2x) = 3 \ 2x - 21 + 6x = 3 \ 8x - 21 = 3 \ 8x - 21 + 21 = 3 + 21 \ 8x = 3 + 21 \ 8x = 24 div 8 \ x = 3 \ \ 30 - x = 3(20 - x) \ 30 - x = 60 - 3x \ - x + 3x = 60 - 30 \ - x + 3x \ - 1x + 3x \ ( - 1 + 3)x = 2x \ 2x = 30 div 2 \ x = 15 \ \ - y + 8 - 14y = 23 \ - 15y + 8 = 23 \ - 15y + 8 - 8 = 23 - 8 \ - 15y = 23 - 8 \ - 15y = 15 div - 15 \ y = - 1.$