Presumably l and m are parallel, so n and p are transversals across parallel lines. They'll make the obvious congruent angles and supplementary angles (add to 180 degrees) that presumably the questions will be asking about.
1. Angle 11 and angle 16. They're what's called vertical angles from a pair of crossing lines. Vertical angles are congruent, so m∠16 = 113°
2. Angle 1 and 3. Those are corresponding angles on a traversal of parallels, also congruent. m∠3 = 78°. You got this one right, good.
3. 7 & 8. They're what's called a linear pair, so are supplemental. 180-129=51 so m∠8 = 51°. You probably just subtracted wrong on this one.
4. 10 & 11. I forgot what these are called; interior angles or some such. Anyway they're supplementary so 180-77=103. m∠11 = 103°
5. 13 & 12. I forgot the name here too but they're congruent so m∠12 = 59°
6. 2 & 7. Again congruent so m∠7 = 130°
7. I don't know why they insist on making geometry into algebra. Here we have angles 1 & 8, which are congruent, so
5x + 2 = 3x + 28
5x - 4x = 28 - 2
2x = 26
x = 13
Answer:
14
Step-by-step explanation:
The perimeter is the sum of the sides, so we have
2x+x+15+4x-7=57
= 7x+8
Subtracting 8 from both sides, we get
7x= 49
Dividing 7 from both sides, we get
x=7
Our sides are then 2x=14, x+15=22, and 4x-7=21. 14 is our answer
Answer: 
Step-by-step explanation:
Vertical Angles states that 9x+27=117
Supplementary Angles states that 117+z=180
![9x+27=117\\Subtract (27)\\9x=90\\Divide(9)\\\left[\begin{array}{c}x=10\end{array}\right] \\\\117+z=180\\Subtract(117)\\\left[\begin{array}{c}z=63\end{array}\right]](https://tex.z-dn.net/?f=9x%2B27%3D117%5C%5CSubtract%20%2827%29%5C%5C9x%3D90%5C%5CDivide%289%29%5C%5C%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%3D10%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C117%2Bz%3D180%5C%5CSubtract%28117%29%5C%5C%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dz%3D63%5Cend%7Barray%7D%5Cright%5D)
<em>Hope it helps <3</em>
Answer:
B) -7
Step-by-step explanation:
x+y
8+(-15)=8-15=-7
