tolong jawab nomor 1.a, b, c dan nomor 2.a

1.) A
y = x^2 - 4x
y = 2x - 5[ - ]
________
0 = x^2 - 4x - 2x + 5
x^2 - 6x + 5 = 0
(x - 6)(x - 1) = 0
x = 6 atau x = 1

y = 2x - 5 = 2(1) - 5 = 3 - 5 = -2
Atau
y = 2x - 5 = 2(6) - 5 = 12 - 5 = 7

b.)
y = x^2 + 2x - 3
y = x + 9 [ - ]
_________
x^2 + 2x - 3 - x - 9 = 0
x^2 + x - 12 = 0
(x - 3)(x + 4) = 0

x = 3 atau x = -4

y = x + 9
y = 3 + 9
y = 12

c.)
y = x^2 - 2x - 8
y = x + 2[ - ]
__________
x^2 - 2x - 8 - x - 2 = 0
x^2 - 3x - 10x = 0
(x - 5)(x + 2) = 0

x = 5 atau x = -2

y = x + 2
y = 5 + 2
y = 7