Question

Rozwiąż równanie.
a. x^3 + 64 = 0
b. 8x^3 - 27 = 0
c. 2x^3 - 128 = 0
d. 5x^3 + 135 = 0
e. 128x^3 -54 = 0
f. 162x^3 + 48 = 0

Answer 1

a.
x^3 + 64 = 0
x³ = -64
x = pierw.trzeciego-st.-64
x = -4
b.
8x^3 - 27 = 0
8x³ = 27
x³ = 27/8
x = ∛x³ = ∛(27/8) = 3/2 = 1 1/2
c.
2x^3 - 128 = 0
2x³ = 128
x³ = 64
x = ∛64
x = 4
d.
5x^3 + 135 = 0
5x³ = -135
x³ = -27
x = -3
e.
128x^3 -54 = 0
128x³ = 54
x³ = 54/128 = 27/64
x = ∛(27/64) = 3/4
f.
162x^3 + 48 = 0
162x³ = -48
x³ = -48/162 = -16/54 =-8/27           
x = ∛(-8/27) = -2/3