Question

I need help with these three

Answer 1

A. The relationship of <7 and <8 are that they are vertical angles, and are congruent.

B. Since vertical angles are congruent, you can form an equation where the two measurements equal each other. 

C. 5y-29=3y+19       then plug y into your equation: 5*24-29=91
    2y=48                   and so: <7 = 180-91=89 (and since <8 is congruent)
    y=24                     <8 also equals 89

Your second problem: 
complementary are two angles that add up to 90 degrees.
<B=x, <A=2x
2x+x=90
3x=90
x=30       so: <B=30 degrees, <A=60 degrees

Your third problem:
1. Since A and B are parallel, angle 3x+7 and angle 4x+5 are same-sided exterior angles. That means that they both add up to 180 degrees. So if you should add the two and make it equal 180
2. 3x+7+4x+5=180
    7x+12=180
    7x=168
    x=24
3. <6 is a corresponding angle with angle 3x+7, meaning that they are congruent. So plug x into 3x+7: 3*24+7=79 and since <6 is congruent to 3x+7, <6=79 degrees

Answer 2

Same side exterior angles are supplementary(adds up to 180 degrees)

(3x+7)+(4x+5)=180
7x+12=180
   -12   -12
7x/7=168/7

x=24
check your answer: 
4(24)+5=101
3(24)+7=79   79+101= 180

measure 6: x
adjacent angles are supplementary 
(4x+5)+ x=180
5x+5=180
   -5   -5
5x/5=175/5
x=35=measre angle 6
4(35)+5=145   145+35=180

yay your done, if you remember which angles are supplementary and which are equal youll be fine. vertical angles are always equal example: angle 1 and 3