1)3[x+3]-[5x-2]=3 2) 6x-12=x^2[x-2] 3) x^4-13x^2+36=0

1) 3(x+3)-(5x-2)=3 3x+9-5x-2=3 3x-5x-2+9=3 -2x+7=3 |*(-1) 2x-7=3 2x-7-3=0 2x=-10 x=-5 

1)3(x+3)-(5x-2)=3 3х+9-5х+2=3 3х-5х=3=3-2-9 -2х=-8 х=-8:(-2) х=4 проверка:   3(4+3)-(5*4-2)=3