I will give brainliest and 20 points to whoever answers or helps me with these 5 questions.

Step-by-step explanation:

1)3x+21=6x-60

81=3x

x=27

3 times 27-21

=81-21

=60

Equation:3x+21=6x-60

Value of x:27

Angle measures:60 & 60

2)12x-18=8x+10

4x=28

x=7

12 times 7-18

=84-18

=66

Equation:12x-18=8x+10

Value of x:7

Angle measures:66 & 66

3)7x+9+5x+3=180

12x+12=180

12x=168

x=14

7 times 14+9

=98+9

=107

5 times 14+3

=70+3

=73

Equation:7x+9+5x+3=180

Value of x:14

Angle measures:107 & 73

4)3x+10+3x-28=180

6x-18=180

6x=198

x=33

3 times 33+10

=99+10

=109

3 times 33-28

=99-28

=71

Equation: 3x+10+3x-28=180

Value of x: 33

Angle measures:109 & 71

5)12x+15=15x

15=3x

x=5

15 times 5

=75

Equation:12x+15=15x

Value of x:5

Angle measures:75 & 75

Hope I helped!!!

D I think

Correct me if I'm wrong