1) \ 2x+7>1 \ x-3<1 \ matrix 2x>1-7\\ x<1+3 matrix ] aligned \ x>(-6)/2\\ \ x<4 \ matrix x>-3\\ x<4 matrix x in(-3;4) 2) \ 3y<21 \ 4-y>0 aligned \ y<21/3\\ \ 4>y {y<7 \ y<4 y in(- infty, ) 3) \ 4x+9>-15 \ 2-x<5 (4x> -15 -9