Question

What would be the reasons for lines 3 and 4? A. Addition property; subtraction property B. Addition property; solve C. Substitution property; subtraction property D. Substitution property; prove

Answer 1

Answer:

C

Step-by-step explanation:

We are given that angle 1 and angle 2 are supplementary angles.

$m\angle 1=128^{\circ}$

We  have to find the reason for line 3 and 4.

1.Angle 1 and angle 2 are supplementary angles

$m\angle 1=128^{\circ}$

Reason:Given

2.$m\angle 1+m\angle2=180^{\circ}$

Reason:Definition of supplementary angles.

3.$128^{\circ}+m\angle 2=180^{\circ}$

Reason:Substitute property

4.$m\angle 2=180-128=52^{\circ}$

Reason:Subtraction property of equality

Hence, option  C is true.

Answer 2

Answer:

I chose

D. Substitution property; prove