Question

Vladimir says that the equation of the line that passes through points (negative 5, negative 3) and (10, 9) is y = four-fifths x + 1. Robyn says that the line passes through the points (negative 10, negative 7) and (negative 15, negative 11). Who is correct?
only Vladimir
only Robyn
both Vladimir and Robyn
neither Vladimir nor Robyn

Answer 1

both Vladimir and Robyn

Both point pairs give slope (9 - (−3))/(10 - (−5)) = 12/15 = 4/5 and (−11 - (−7))/(−15 - (−10)) = −4/−5 = 4/5, and each yields intercept b = 1, so the line is y = (4/5)x + 1.