Question

Rozwiąż równanie.

a) |x - 4| + |3x - 12| = 20
b) |x + 8| + |2x + 16| = 21
c) |4x - 20| + |x - 5| = 5
d) |x - 3| - |4x - 12| = -30

Answer 1

Odpowiedź:

a) x = 8

b) x = -1

c) x = 6

d) x = 13

Szczegółowe wyjaśnienie:

a) (x-4) + (3x-12) = 20

x - 4 + 3x - 12 = 20

4x - 16 = 20 /+16

4x = 32 /:4

x = 8

b) (x + 8) + (2x + 16) = 21

x + 8 + 2x + 16 = 21

3x + 24 = 21 / -24

3x = -3 /:3

x = -1

c) (4x - 20) + (x - 5) = 5

4x - 20 + x - 5 = 5

5x - 25 = 5 /+25

5x = 30 /:5

x = 6

d) (x - 3) - (4x - 12) = -30

x - 3 - 4x + 12 = -30

- 3x + 9 = - 30 / -9

- 3x = -39 / : (-3)

x = 13