1. a + b = 11 a= a × b = 3a b= 2.a + b = -1 a= a × b = -12 b= 3.a + b = -10 a= a × b = 21 b= jawab please :

1. a x b = 3a ↝ b = 3a/a = 3
a + b = 11↝a + 3 = 11↝a = 11 - 3 = 7

2. a x b = -12 ↝ a = -12/b
a + b = -1 ↝ (-12/b) + b = -1
(-12+b²)/b = -1
-12 + b² = -1 x b
b² - 12 = -b
b² + b - 12 = 0
(b - 3)(b + 4) = 0
b1 = 3 ∨ b2 = -4

#b1 = 3 ↝ a + b = -1
a + 3 = -1 ↝a = -1 - 3 = -4
#b2 = -4 ↝ a + b = -1
a + (-4) = -1 ↝ a = -1 + 4 = 3

jadi (a,b) ↝ (-4,3) ∨ (3,-4)

3. a + b = -10 ↝ a = -10 - b
a x b = 21 ↝ (-10 - b) x b = 21
-10b - b² = 21
b² + 10b + 21 = 0
(b + 3)(b + 7) = 0
b1 = -3 ∨ b2 = -7

#b1 = -3 ↝ a + b = -10
a + (-3) = -10 ↝a = -10 + 3 = -7
#b2 = -7 ↝ a + b = -10
a + (-7) = -10 ↝ a = -10 + 7 = -3

jadi (a,b) ↝ (-7,-3) ∨ (-3,-7)

semoga membantu ^^