1. y = x^{2} - 2x - 1 y= x^{2}-1 2. x^{2} - y - 1 =0 x - y - 3 = 0 3. jika x dan y merupakan penyelesaian dari sistem persamaan x-4y=26 dan 3x+2y=8,maka nilai 9

1. y = x² - 2x - 1
y = x² - 1

gabung keduanya , didapat
x² - 2x - 1 = x² - 1
0 = 2x
x = 0

y = x² - 1
y = 0² - 1
y = -1

HP : {0 , -1}

2.
x² - y - 1 = 0
x² - 1 = y ... (i)

x - y - 3 = 0
x - 3 = y ... (ii)

Gabung (i) dan (ii)

x² - 1 = x - 3
x² - x + 2 = 0
Didapat , a = 1 , b = -1 , c = 2

D = b² - 4ac
D = (-1)² - 4(1)(2)
D = -7

Karena D < 0 , maka Tidak ada bil. real yg memenuhi
HP : { }

3.
x - 4y = 26
x = 26 + 4y

Maka

3x + 2y = 8
3(26 + 4y) + 2y = 8
78 + 12y + 2y = 8
14y = -70
y = -5

x = 26 + 4(-5)
x = 6

9 / (x - y) = 9 / (6 + 5) = 9/11

4.
(3,2) –> 3a + 2b = 5
(2,-1) –> 2a - b = 8 , b = 2a - 8

Maka
3a + 2(2a - 8) = 5
3a + 4a - 16 = 5
7a = 21
a = 3

b = 2a - 8
b = 2(3) - 8
b = -2

a - b = 3 + 2 = 5

5.
y = x² + 3x - 10
y = 4x + 10

Maka
x² + 3x - 10 = 4x + 10
x² - x - 20 = 0
(x - 5)(x + 4) = 0
x = 5 V x = -4

Utk x = -4
y = 4(-4) + 10
y = -6

Utk x = 5
y = 4(5) + 10
y = 30

HP : {(5 , 30) , (-4 , -6)}

6.
2x +2y - 2 = x - 3y
x = -5y + 2

Maka
3x - 6 + 3y = x - y
2x + 4y = 6
2(-5y + 2) + 4y = 6
-10y + 4 + 4y = 6
-6y = 2
y = - ⅓

x = -5(- ⅓) + 2
x = 11/3

HP : {11/3 , - ⅓}