Uraikan sistem persamaan berikut dengan substitusi a. y = 3x 2x+7y=46 b. 4x-5y=7 x+3y+1=0 c. x-4y=11 4x+7y+2=0 d. 19x-y-24=0 9x+4y+11=0

a) y = 3x
subtitusi
2x + 7y = 46
2x + 7(3x) = 46
2x + 21x = 46
23x = 46
x = 2
subtitusi
y = 3x
y = 3(2)
y = 6
hp = ( 2 ,6 )

b) x + 3y + 1 = 0
x = - 3y - 1
subtitusi
4x - 5y = 7
4(-3y-1 ) - 5y = 7
- 12y + 4 - 5y = 7
- 17y = 7 - 4
- 17y = 3
y = - 3/17
subtitusi
x = - 3y - 1
x = - 3(-3/17) - 1
x = 9/17 - 17/17
x = - 8/17
hp = ( - 8/17 , - 3/17 )

c) x - 4y = 11
x = 4y + 11
subtitusi
4x + 7y + 2 = 0
4(4y + 11 ) + 7y + 2 = 0
16y + 44 + 7y + 2 = 0
23y + 46 = 0
23y = - 46
y = - 2
subtitusi
x = 4y + 11
x = 4(-2) + 11
x = - 8 + 11
x = 3
hp = ( 3, - 2)

d) 19x - y - 24 = 0
- y = - 19x + 24
y = 19x - 24
subtitusi
9x + 4y + 11 = 0
9x + 4(19x - 24) + 11 = 0
9x + 76x - 96 + 11 = 0
85x - 85 = 0
85x = 85
x = 1
subtitusi
y = 19x - 24
y = 19(1) - 24
y = 19 - 24
y = - 5
hp = ( 1 , - 5 )