Jawab:
(1.) 9x² - 4 = 0
(3x + 2)(3x-2) = 0
Hp = {-⅔, ⅔}

(2.) 2x² + 5x - 3 = 0
(2x-1) (x+3) = 0
Hp = {½, -3}

(3.) 4a(a+1) = 15
(2a-3) (2a+5) = 0
Hp = {³/₂, -⁵/₂}

(4.) m² - m - 6 = 0
(m + 2)(m - 3) = 0
Hp = {-2, 3}

Penjelasan :
(1.) 9x² - 4 = 0
(3x)² - 2² = 0
a² - b² = (a+b)(a-b)
(3x + 2)(3x-2) = 0
Hp = {-⅔, ⅔}

(2.) 2x² + 5x - 3 = 0
a = 2
x² + 5x - 3(2) =0
x² + 5x - 6 = 0
b = 5, c = -6
b+c = 5, bc = -6
-1+6 = 5, -1(6) = -6
b = -1, c = 6
¹/ₐ (ax+b)(ax+c) = 0
½ (2x-1) (2x+6) = 0
(2x-1) (²/₂x+⁶/₂) = 0
(2x-1) (x+3) = 0
Hp = {½, -3}

(3.) 4a(a+1) = 15
a(a+1) = ¹⁵/₄
a² + a = ¹⁵/₄
a² + a + (½)² = ¹⁵/₄ + (½)²
a² + 2a(½) + (½)² = ¹⁵/₄ + ¼
(a + ½)² = ¹⁶/₄
(a + ½)² = 4
a + ½ = ±√4
a + ½ = ±2
a = ±2 - ½
Hp = {2 - ½, -2 - ½}
Hp = {⁴/₂ - ½, -⁴/₂ - ½}
Hp = {³/₂, -⁵/₂}
(2a-3) (2a+5) = 0
Hp = {³/₂, -⁵/₂}

(4.) m² - m - 6 = 0
ab = -6, a + b = -1
2(-3) = -6, 2 - 3 = -1
a = 2, b = -3
(m + a)(m + b) = 0
(m + 2)(m - 3) = 0
Hp = {-2, 3}

(xcvi)