Question

Tentukan persamaan garis yang melalui titik potong 4x+7y-15=0 dan 14y=9x-4 serta tegak lurus garis 21x+5y=3

cepet yaa.. hehe thanks

Answer 1

8x+14y=30
9x-14y=4  -
17x=34
x=2

8x+14y=30
8(2)+14y=30
14y=30-16
14y=14
y=1

jadi titik potonnya(2,1)
m1=-a/b=-21/5
m2=5/21

masukkan ke rumus y-b=m2(x-a)
y-1=5/21(x-2)
y=5/21x-10/21+1
y=5/21x-10/21+21/21
y=5/21x-11/21
atau 21y-5x-11=0

Answer 2

Tentukan persamaan garis yang melalui titik potong 4x+7y-15=0 dan 14y=9x-4 serta tegak lurus garis 21x+5y=3
jawab:
4x+7y-15=0  x 2 : 8x +14y -30 =0
9x-14y -4= 0 x 1 : 9x -14y - 4 = 0
----------------------------------------- +
17x - 34 =0
x = 34/17 = 2
14y = 9(2) - 4
y = 14/14 = 1................koordinat (2,1)

21x+5y = 3
5y = -21x +3
y = -21/5x + 3/5.........m1 = -21/5

m =-1/m1 = -1/(-21/5) = 5/21

y-y1 = m(x-x1).............(2,1)
y-1 = 5/21(x-2)
21y-21 = 5x -10
5x -21y + 11 = 0