Someone, answer all questions with an explanation for each question!

5) The angles are vertical so they are congruent.

3x - 10 = 2x + 30
3x = 2x + 40
x = 40

6) To calculate x we will have to find a first.

5a + 4a = 180 because they are on a straight line.

9a = 180
a = 20

Now we will find the value of 5a because x is vertical to the angle, hence they are congruent.

So 5a = 5(20) = 100

So angle x is also 100.

7) First we will find the value of x.

6x - 25 = 4x + 15
6x = 4x + 40
2x = 40
x = 20

The value of y can be found now by setting 4x + 15 + y = 180 becuase they are on a straight line.

4(20) + 15 + y = 180
80 + 15 + y = 180
95 + y = 180
y = 85.

Hope this helps :)

Ithink if im not mistaking b is -3 but im not a 100% sude