Answer:
[(x + 3) (x + 7)] / (3x + 21)
= [(x + 3) (x + 7)] / [3 (x + 7)]
= (x + 3) / 3
The denominator can't be equal to 0 therefore:
3 (x + 7) ≠ 0 ⇔ x + 7 ≠ 0 ⇔ x ≠ -7
Two column proofs are organized into statement and reason columns. Each statement must be justified in the reason column. Before beginning a two column proof, start by working backwards from the "prove" or "show" statement. The reason column will typically include "given", vocabulary definitions, conjectures, and theorems.
The answer is x=-15/2
Im not sure how to explain it I’m sorry
Answer:
Step-by-step explanation:
we know that
An exterior angle of a triangle is equal to the sum of the opposite interior angles.
see the attached figure to better understand the problem
so
∠DEF=∠ECD+∠CDE
substitute the given values
solve for x
Combine like terms
Group terms
Find the measure of angle CDE
substitute the value of x
