Aline passes through the points (–1, –5) and (4, 5). the point (a, 1) is also on the line.

Find the equation of the line through the points (–1, –5) and (4, 5).  First, find the slope:  m = rise / run = 5/10 = 1/2.

Then the equation is y-5=(1/2)(x-4).  If (a,1) is on this line, (a,1) must satisfy the given equation.  Let y=1 and solve for x:

1-5 = (1/2)(x-4)   Mult both sides by 2 to get -2 = x-4.   Then x = -4+2 = -2

So (-2,1) is also on the line.

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.