Sistem persamaan linear satu variabel ( Peubah ) Persamaan Linear Satu Variabel adlh suatu kalimat terbuka yg hanya memuat sebuah variabel dan pangkatnya satu. Bentuk Umum : ax + b = 0 dg a ≠ 0 dan a, b ϵ R Contoh : Tentukan nilai x dari : a) 3x + 5 = x – 1 b) 2x – 4 = 12 ⇔ 3x – x = - 1 – 5 ⇔ 2x = 12 + 4 ⇔ 2x = - 6 ⇔ 2x = 16 ⇔ x = - 3 ⇔ x = 8
Tentukan Himpunan Penyelesaian (HP) persamaan berikut ! 5n – 7 = 2n + 2 2y – 3 = 3y – 7 4x – 19 = 17 – 8x 5 + 3(2 – x) – 2 = 2(x – 3) 8x – 3 = 4(x + 1) + 5
Jawab 5n - 7 = 2n + 2 3) 4x – 19 = 17 – 8x ⇔ 5n – 2n = 2 + 7 ⇔ 4x + 8x = 17 + 19 ⇔ 3n = 9 ⇔ 12x = 36 ⇔ n = 3 ⇔ x = 3 ؞HP = { 3 } ؞HP = { 3 } 2) 2y – 3 = 3y -7 4) 5 + 3(2 – x) – 2 = 2(x – 3) ⇔ 2y – 3y = -7 + 3 ⇔ 5 + 6 – 3x – 2 = 2x - 6 ⇔ - y = - 4 ⇔ - 3x – 2x = - 6 – 5 – 6 + 2 ⇔ y = 4 ⇔ - 5x = -15 ؞HP { 4 } ⇔ x = 3 ؞HP = { 3 }
5) 8x – 3 = 4(x + 1) + 5 6) 7) ⇔ 8x – 3 = 4x + 4 + 5 ⇔ 8x – 4x = 4 + 5 + 3 ⇔ 4x = 12 ⇔ 4y = 3(y + 2) ⇔ 4y = 3y + 6 ⇔ 4y – 3y = 6 ⇔ x = 3 ⇔ y = 6 ؞ HP = { 3 } ⇔ x.1 = 2.6 ؞HP = { 6 } ⇔ x = 12 ؞ HP = { 12 }
( x 12 ) ( x 12 ) ⇔ 2(3x - 5) – 3(3x – x) + 3(x + 5) = 0 ⇔ 6(3x) + 3(3x) = 2(x – 5) ⇔ 6x – 10 – 9x + 3x + 3x + 15 = 0 ⇔ 18x + 9x = 2x – 10 ⇔ 6x – 9x + 3x + 3x = 10 – 15 ⇔ 18x + 9x – 2x = - 10 ⇔ 3x = - 5 ⇔ 25x = - 10 ⇔ ⇔ ( x 20) ⇔ 4(3x) – 10(1x) = 5(2x – 3) ⇔ - 8x = - 15 ⇔ 12x – 10x = 10x – 15 ⇔ 12x – 10x – 10x = - 15 ⇔
Tentukan hp Persamaan Berikut ! 5x – 2 = 3x + 10 5x + 2(x – 4) = 4(x – 2) – 7(x + 4)
Jawab 5x – 2 = 3x + 10 ⇔ 5x – 3x = 10 + 2 ⇔ 2x = 12 (x 3) ⇔ x = 6 ؞ HP = { 6 } ⇔ 1(7x + 2) = 3(4x – 1) ⇔ 7x + 2 = 12x – 3 2) 5x + 2(x – 4) = 4(x – 2) – 7(x + 4) ⇔ 7x – 12x = - 3 – 2 ⇔ 5x + 2x – 8 = 4x – 8 – 7x – 28 ⇔ - 5x = - 5 ⇔ 5x + 2x – 4x + 7x = - 8 – 28 + 8 ⇔ x = 1 ⇔ 10x = - 28 ؞ HP = { 1 } ⇔