Question

Kak tolong bantuin ngerjain mtk nomor 4.C, dan 5.D. dengan caranya untuk dikumpulkan besok.

Answer 1

4c.
-4 ≤ 3x +5 ≤ 8
-4-5 ≤ 3x ≤ 8-5    (ketiga ruas dikurang 5)
-9 ≤ 3x ≤ 3
-9/3 ≤ x ≤ 3/3    (ketiga ruas dibagi 3)
-3 ≤ x ≤ 1
HP = (x Ι -3 ≤ x ≤ 1}

5d.
x-1 ≤ 2x +1 ≤ 3+x
x-1-x ≤ 2x +1-x ≤ 3+x-x   (ketiga ruas dikurang x)
-1 ≤ x +1 ≤ 3
-1 - 1 ≤ x +1 -1 ≤ 3 - 1   (ketiga ruas dikurang 1)
-2 ≤ x ≤ 2

HP = (x Ι -2 ≤ x ≤ 2}

Answer 2

[4c].

- 4 ≤ 3x + 5 ≤ 8

- 4 - 5 ≤ 3x + 5 - 5 ≤ 8 - 5    [semua ruas dikurangi 5 agar hanya 3x di bagian tengah]

- 9 ≤ 3x ≤ 3

[- 9]/3 ≤ [3x]/3 ≤ [3]/3          [semua ruas dibagi 3 agar bagian tengah hanya x)

Diperoleh -3 ≤ x ≤ 1

∴ HP = { x Ι - 3 ≤ x ≤ 1, x ∈ R }

[5d].

x - 1 ≤ 2x + 1 ≤ 3 + x

x - 1 - x ≤ 2x + 1 - x ≤ 3 + x - x   [semua ruas dikurangi x agar hanya 2x di bagian tengah]

- 1 ≤ x + 1 ≤ 3

- 1 - 1 ≤ x + 1 - 1 ≤ 3 - 1   [semua ruas dikurang 1 agar hanya x di bagian tengah]

Diperoleh - 2 ≤ x ≤ 2

∴ HP = { x Ι - 2 ≤ x ≤ 2, x ∈ R }