tolong dijawab no.4 trimakasih

m1 = ( y2 - y1) / ( x2 - x1)
m1 = ( 4 - 3 ) / ( 3 - 1 )
m1 = 1 / 2

gradien saling tegak lurus
m1 . m2 = - 1
½ . m2 = - 1
m2 = - 1 ÷ ½
m2 = - 2

pers garis
y - y1 = m ( x - x1 )
y - 4 = - 2 ( x + 2)
y = - 2x - 4 + 4
y = - 2x