tolong yang dilingkari jawaban beserta caranya

1) 3x + 5y + 20 = 0
5y = - 3x - 20
m = -3/5
gradien tegak lurus
m1 . m2 = - 1
- 3/5 . m2 = - 1
m2 = 5/3 ( D)

2) m = ( y2 - y1 ) / ( x2 - x1 )
m = ( 7 - 1 ) / ( 4 - 2)
m = 6 / 2
m = 3 ( D)

3) m = ( y2 - y1) / ( x2 - x1)
m = ( 6 - 1) / ( 3 - 2)
m = 5 / 1
m = 5
gradien sejajar m1 = m2 = 5
y - 5x + 12 = 0
y = 5x - 12
m = 5/1
m = 5
jadi yg sejajar garis (i) ( A)

4) 2x - 3y = 18
x + 4y = - 2 |×2
maka
2x - 3y = 18
2x + 8y = - 4
-------------------(-)
- 11y = 22
y = - 2
subtitusi ke pers
x + 4y = - 2
x + 4(-2) = - 2
x - 8 = - 2
x = - 2 + 8
x = 6
nilai x + y
= 6 - 2
= 4 ( C )