If the three lines above all intersect at exactly one point, what is the value m + b?

[BTGmoderatorDC]

y = mx − 7
y = 12x + b
y = x + 1

If the three lines above all intersect at exactly one point, what is the value m + b?

(1) The x−coordinate at the point where all three lines meet is 8.

(2) The y−coordinate at the point where all three lines meet is 9.


OA D

Source: Veritas Prep