|x+4| + |x-5| = 20 tolong bantu pake cara ya

Materi : Persamaan Mutlak

Pembahasan :
|x + 4| + |x - 5| = 20
(x + 4 + x - 5)² = 20²
(2x - 1)² = 20²
(2x - 1)² - 20² = 0
(2x - 1 + 20)(2x - 1 - 20) = 0
(2x + 19)(2x - 21) = 0
x = -19/2
x = 21/2

Hp : {-19/2 , 21/2}