What is the angle between the two lines y=5x+2y = 5x + 2y=5x+2 and y=−2x+7y = -2x + 7y=−2x+7?
45∘45^\circ45∘
90∘90^\circ90∘
arctan(7/9)\arctan(7/9)arctan(7/9)
arctan(9/7)\arctan(9/7)arctan(9/7)