The formula y y-y1=m(x-x1) please tell me what is m

Nick estimated that 5/8+4/7 is about 2.explain how you know his estimate is not reasonable plz and fast i will give 50 points

Find the slope of a line given the following two points

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.