Question

Disini ada 6 pertanyaan!! tolong dijawab pake PEMBAHASAN!! HARUS PAKE PEMBAHASAN!!!
thanks

Answer 1

1) (A)
x^2 + 2x -5 = x+1
x^2 + 2x - x -5 - 1= 0
x^2 + x -6 = 0
(x+3)(x-2) =-
x = -3 atau x = 2
x = -3 --> y = x+1 = -2 -->(-3, 2)
x = 2 --> y = 3 --> (2,3)
.
2. (tidak ada di option)
2x^2 - 5x - 17 = -3x - 5
2x^2 - 2x - 12= 0
(2x - 6)(x +2) = 0
x = 3 --> y = -3x-5 = -14
x = -2 -->y = -3x-5 = 1
(3, -14), (-2, 1)
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3)
2x-y + 3 = 0
y = 2x+3  ...(1)

x^2 -x +y -5= 0
Y = -x^2 + x + 5 ...(2)
.
(1) = (2)
2x+3 =  -x^2 +x +5
x^2 + 2x - x +3 -5= 0
x^2 + x -2 = 0
(x+2)(x-1) = 0
x = -2 atat x  = 1
x= -2 --> y = 2x+3 = -1
x = 1 --> y = 5
nilai  y0^2 - y1^2 =  5^2 - (-1)^2 = 25-1 = 24

4.
x^2 + x -2 = px - 2
x^2 +(1-p) x = 0
D= 0
(1-p)^2 - 4(a)(0)= 0
1-p = 0
p = 1
.
5)
x^2 - 4x +5 = 2x - b
x^2 - 6x +5+b = 0
D> 0
(-6)^2 - 4(1)(5+b) > 0
36 -20- 4b > 0
-4b > -16
b < 4
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6) 
x^2 + y^2 = 25-> y^2 = 25 - x^2
y + 2x = 10 -->  y = 10 - 2x
(10-2x)^2 = 25 - x^2
100 - 40 x + 4x^2 = 25 - x^2
5x^2 - 40 x + 75 = 0
x^2 - 8x + 15 =  0
(x-5)(x-3) = 0
x = 5 --> y = 10- 2x = 0
x = 3 --> y = 10-2x = 4
.
2(y1+y2) = 2(0+4)= 8