tolong ya kak terimakasih sebelumnya hehe

7) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( 9 - 5 ) / ( 4 - 2 )
= 4 / 2
= 2
mI2 = ( y2 - y1 ) / ( x2 - x1 )
= ( 2 - 4 ) / ( 3 + 1 )
= - 2 / 4
= - ½
mI1 . mI2 = 2 . - ½ = - 1
garis saling tegak lurus

8) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( 2 + 5 ) / ( - 1 + 3)
= 7 / 2
mI2 = ( y2 - y1 ) / ( x2 - x1 )
= ( 2 - 4 ) / ( 7 - 0)
= - 2 / 7
mI1 . mI2 = 7/2 . - 2/7 = - 1
garis saling tegak lurus

9) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( - 1 + 2 ) / ( 3 - 4)
= 1 / - 1
= - 1
mI2 = ( y2 - y1 ) / ( x2 - x1 )
= ( - 16 + 1 ) / ( - 10 + 5)
= - 15 / - 5
= 3
kedua garis tdk sejajar & tdk tegak lurus

10) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( 3 - 0 ) / ( 2 - 0)
= 3/2
mI2 = ( y2 - y1 ) / ( x2 - x1 )
= ( - 2 - 5 ) / ( 0 + 2)
= - 7 / 2
kedua garis tdk sejajar & tdk tegak lurus

11) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( 9 - 3) / ( 5 - 5 )
= 6/0
= 0
mI2 = ( y2 - y1 ) / ( x2 - x1)
= ( 2 - 2 ) / ( 0 - 4 )
= 0 / - 4
= 0
mI1 = mI2 = 0
kedua garis sejajar

12) mI1 = ( y2 - y1 ) / ( x2 - x1 )
= ( 5 - 5 ) / ( 2 - 3)
= 0 / - 1
= 0
mI2 = ( y2 - y1 ) / ( x2 - x1 )
= ( 4 - 4 ) / ( 0 - 2)
= 0 / - 2
= 0
mI1 = mI2 = 0
kedua garis sejajar