Step-by-step explanation:
6. angle 1 = angle 4 = 60deg (vertically opposite angles)
7. angle 3 = 180 - 40 - 60 = 80deg (angles on a straight line are supplementary)
8. angle 5 = angle 2 = 40deg (vertically opposite angles)
9. angle 6 = angle 3 = 80deg (vertically opposite angles)
10. angle 7 = angle 5 + angle 4 = 40 + 60 = 100deg (alternate angles, //lines)
11. angle 8 = 180 - 100 = 80deg (angles on a str line are supplementary)
12. angle 9 = 180 - 80 - 40 = 60deg (angles in a triangle)
13. angle 10 = 180 - 60 = 120deg (angles on a str line are supplementary)
14. angle 11 = angle 9 = 60deg (vertically opp angles)
15. angle 12 = angle 10 = 120deg (vertically opp angles)
Topic: angles
If you like to venture further, feel free to check out my insta (learntionary). It would be best if you could give it a follow. I'll be constantly posting math tips and notes! Thanks!
27x - 144 + 15 = 6x - 24
27x - 129 = 6x - 24
+129 +129
--------- --------
0 105
27x = 6x + 105
-6x -6x
----- ------
21x 0
21x = 105
21x/21 = 105/21
x = 5
Remove brackets
Gather like terms
Get rid of the lone number
Transfer
Divide
Hope this helps :)
Answer:
x = 67.5°
Step-by-step explanation:
A circle's angles add up to 360°
So,
x+3x+90 = 360
4x+90 = 360
4x = 360-90
4x = 270
Dividing both sides by 4
x = 67.5°
Answer:
Dont think eh multiplied both sides by 4. That would be the first step.
Step-by-step explanation:
1/4(x+12)=2
multiply both sides by 4
x+12=8
move the 8 to the right side of the equation and change its sign
x=8-12
calculate
x= -4