Многочлены

(решите уравнение)

(3x-8) - (7x+1) = 21

5-7x=11x-3 (x+5)

(3x - 8) - (7x + 1) = 21

3x - 8 - 7x - 1 = 21

-4x - 9 = 21

-4x = 21 + 9

-4x = 30

x = - 30:4

x = - 7,5

5 - 7x = 11x - 3 (x + 5)

5 - 7x = 11x - 3x - 15

-7x - 11x + 3x = - 15 - 5

-15x = - 20

15x = 20

x = 20:15

x = 4/3 = 1 1/3

(3 х-8) - (7 х+1) = 21

3 х-8-7 х-1=21

3 х-7 х=21+1+8

-4 х=30

х=30: (-4)

х=-7,5

Проверка

((3*-7,5) - 8)) - ((7*-7,5)) + 1) = 21

(-22,5-8) - (-52,5+1) = 21

-30,5+51,5=21

21=21

5-7 х=11 х-3 (х+5)

5-7 х=11 х-3 х-15

-7 х-11 х+3 х=-5-15

-15 х=-20

х=-20: (-15)

х=20/15=4/3=1.1/3