1) (2-x)(8-x) 0 2) (1-x)(7-x) 0 3) (x-2)(5+x) 0 - вопрос №1280217032508236561 от kpy4 01.11.2020 03:36

Question

Алгебра: 1) (2-x)(8-x) 0 2) (1-x)(7-x) 0 3) (x-2)(5+x) 0

kpy4 · Answer

1) 16-2x-8x+x² 0 x²-10x+16=0D= b²-4ac = 100-64= 36x1= -b-√D = 10-6 2a. = 2 2 x2= -b+√D = 10+6 2a. = 8 2 + - +——•——•———› 2 8(-∞;2)€(8;∞) 2) 7-x-7x+x² 0 x²-8x+7=0D=b²-4ac= 64-28=36 x1= -b-√D = 8-6 =1 2a. 2x2= -b+√D = 8+6 2a. = 7 2 +. - + ———•——•——› 1 7(-∞;1)€(7;∞) 3)5x+x²-10-2x 0 x²+3x-10=0 D=b²-4ac= 9+40=49 x1= -b-√D = -3-7 2a. = -5 2x2= -b+√D = -3+7 2a. = 2 2 + - +———•————•———› -5 2(-∞;-5)€(2;∞)...

1) (2-x)(8-x)< 0 2) (1-x)(7-x)> 0 3) (x-2)(5+x)> 0