Penjelasan dengan langkah-langkah:

3. x²+y²-8x-4y-20=0

(x²-8×+16)-16+(y²-4y+4)-4-20=0

(x-4)² + (y-2)² = 40

▪︎m=3

▪︎PGS

(y-2) = 3(x-4)±akar40.akar(3²+1)

y-2 = 3x-12±akar400

y-2 = 3x-12±20

3x-y = 10±20(3x-y=30 atau 3x-y=-10)

4. a. -4y = -3x-5

m = 3/4(sejajar)

(x²+4x+4)-4+(y²-6y+9)-9-7=0

(x+2)²+(y-3)²=20

PGS

(y-3)=3/4 × (x+2)±akar20.akar((3/4)²+1)

y-3 = (3/4)x + 3/2 ±akar20.akar25/16

y-3 = (3/4)x + 3/2±akar400/16

y-3 = (3/4)x + 3/2±akar25

y-3 = (3/4)x + 3/2±5 (dikalikn 4)

4y-12 = 3x +6 ±5

3x-4y = -18±5

(3x-4y= -23 atau 3x-4y = -13)

b. y = -2x -4

tegak lurus : mtl= -1/(m) =-1/-2 = 1/2

PGS

(y-3) = 1/2(x+2)±akar20.akar((1/2)²+1)

y-3 = (1/2)x + 1 ± akar20.akar5/4

y-3=(1/2)x +1 ± akar100/4

y-3 = (1/2)x + 1 ±akar 25

y-3 = (1/2)x + 1 ±5 (dikalikan 2)

2y-6 = x+2±10

(x-2y= -18 atau x-2y= 2)

cek lagi ya