Johnny can buy two 8-foot pieces of 2" by 4" lumber at $2.60 each, or three 6-foot pieces for $1.92 each. which is the better buy per foot?

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.

Solve each quadratic equation by factoring and using the zero product property. [tex]x^2+6x+8=0[/tex]

Collin did the work to see if 10 is a solution to the equation r/4=2.4