Question

Решите неравенство 1) (x-5)(x+5)-x(x+3)6y-20 3) (x+2)(x-6)-(x-7)(x+7)<30-3x 4) x(8-3x)+11<3(7-x)(x+7)+8 Помощь Людии

Answer 1

3)(x+2)(x-6)-(x-7)(x+7)<30x-3x
x²-6x+2x-12-x²+7x-7x-49<27x
-4x-61<27x
61<31x
x<31/61
4)x(8-3x)+11<3(7-x)(x+7)+8
8x-3x²+11<21-3x(x+7)+8
11-21+8<3x²-8x-3x(x+7)
-2<3x²-8x-3x²-7x
-2<-15x
x<2/15