Answer:
the answer is the last one
Step-by-step explanation:
Answer:
53
Step-by-step explanation:
At first,
- 7 = 9 + x
By subtracting 9 from both sides, we get
-7-9=9+x-9
-16=x
Now,
By substituting the value of x in -3x + 5 , we get
-3x + 5
-3×(-16)+5
48+5
53
Answer:
22.5°
Step-by-step explanation:
First we need to figure out the size of the interior angles on the inside.
The formula of figuring out the total degrees of all the interior angles of any shape is (n-2)×180°.
N is the number of sides.
If we substitute our number of sides (8) we get this:
(8-2)×180°
6×180° = 1080°
Then we divide 1080 by 8 since this is a regular octagon (all angles are equal in a regular shape).
1080° ÷ 8 = 135°
Focusing on the triangle now, we now know that the angle on the tip of the triangle is 135° as it has not been split by the line.
Using the rule of angles in a triangle add up to 180°. We do this sum:
180° - 135° = 45°
There are 2 angles left in the triangle so we do:
45° ÷ 2 = 22.5°
Therefore the angle of x is 22.5°.
3a+20=-25
Subtract 20 from both sides
3a=-45
Divide both sides by 3
a=-15
Final answer: a=-15
