Operations with variables can give you excluded values by making the denominator equal to zero.
Ex. 48/60 always equals to 4/5 but 4x/6x is not always equal to 2/3 because when you make x equal to zero it makes the equation invalid.
Answer:
-39x+21
Step-by-step explanation:
F: 6x
O: -3x
I: -42x
L: 21
6x-3x-42x+21= -39x+21
Answer:
D) Angle DAC is congruent to Angle BAC
Step-by-step explanation:
Given:
The triangles ABC and ADC are congruent by SAS postulate.
SAS postulate means two corresponding sides are congruent to each other and the included pair of angles are also congruent to each other.
From the figure, consider the triangles ABC and ADC.
AB = AD (Given)
AC = AC ( Reflexive property. Side AC is a common side to both triangles)
Now, the pair of angles included between these two pair of sides are angle BAC and angle DAC.
So, in order to prove the two triangles congruent by SAS postulate, we need to prove angle DAC congruent to angle BAC. Therefore, the correct option is option D.
