Answer:
<h2><u><em>
a²+2ab+b²-c²</em></u></h2>
Step-by-step explanation:
Solve:
(a+b+c) (a+b-c)=
(a²+ab-ac+ab+b²-bc+ac+bc-c²)=
a²+ab-ac+ab+b²-bc+ac+bc-c²=
a²+2ab+0ac+b²+0bc-c²=
a²+2ab+b²-c²
Answer: 
Step-by-step explanation:
By definition, the sum of the exterior angles of a polygon is 360 degrees.
Knowing this, you can write the following equation:

Then, you must solve for "x" in order to find its value. To do it, you can follow these steps:
1. You need to add the like terms:

2. Now, subtract 40 from both sides of the equation:

3. Finally, you must divide both sides of the equation by 4. Then:

Answer:
See below.
Step-by-step explanation:
1.
(a) < PMR
(b) < QMR
(c) < QMN
(d) < RMN
2. m < C = 4x - 6
= 4(25) - 6
= 100 - 6
= 94 so < C is obtuse.
3. 8x + 2 = 90
8x = 90 - 2
8x = 88
x = 11.
4.
(a). < DBA and < DBC are right angles (90 degrees) because BD is perpendicular to AC.
(b) < DBA and < DBC are adjacent and they share the ray BD.
(c) < DBe and < ABE are complementary.
(d) < DBA and < DBC are supplementary
(e) 90 - 40 = 50 degrees
(f) 180 - 40 = 140 degrees.
(g) As the angles are complementary
3x + 2 + 4x + 4 = 90
7x = 90 - 2 - 4
7x = 84
x = 12.
0.00742574257 I'm glad I could help