Tentukan hp dari 1) |2y +5| = |7-2y| 2) |1-9x| ≤ |x+5|

Kelas 10 Matematika
Bab Nilai Mutlak

1] |2y + 5| = |7 - 2y|
(2y + 5)² - (7 - 2y)² = 0
(2y + 5 + 7 - 2y) (2y + 5 - 7 + 2y) = 0
12 . (4y - 2) = 0
4y - 2 = 0
4y = 2
y = 2/4
y = 1/2

HP = { 1/2 }

2] |1 - 9x| ≤ |x + 5|
(1 - 9x)² - (x + 5)² ≤ 0
(1 - 9x + x + 5) (1 - 9x - x - 5) ≤ 0
(-8x + 6) (-10x - 4) ≤ 0
(8x - 6) (10x + 4) ≤ 0
8x - 6 ≤ 0
8x ≤ 6
x ≤ 6/8
x ≤ 3/4

10x + 4 ≥ 0
10x ≥ -4
x ≥ -4/10
x ≥ -2/5
-2/5 ≤ x

HP = { x | -2/5 ≤ x ≤ 3/4, x ∈ bilangan real }