Step-by-step explanation:
Given that,
DE = 8x - 13
EF = 5x + 17
DF = x + 21
Also,
DE = EF
which means that,
8x - 13 = 5x + 17
8x - 5x = 17 + 13
3x = 30
x = 30/3
x = 10
Now,
DE = 8x - 13 = 8×10 - 13 = 80 - 13 = 67cm
EF = 5x + 17 = 5×10 + 17 = 50 + 17 = 67cm
DF = x + 21 = 10 + 21 = 31cm
She would have to score atleast a 74 on the test for her average to be 78
I'm pretty sure the answer is A. hope that helped
9514 1404 393
Answer:
C. 168°
Step-by-step explanation:
The exterior angle at any vertex of an n-gon will be ...
360°/n
So a 30-gon will have exterior angles of ...
360°/30 = 12°
The adjacent interior angle is supplementary to this, so is ...
180° -12° = 168°
_____
<em>Using the reasonableness test</em>
You know that the interior angles of a square are 90°, and that regular polygons with more sides have larger interior angles. The most any regular polygon's interior angle can be is 180°. The only answer choice between 90° and 180° is the correct choice: 168°.
Answer:
See explanation
Step-by-step explanation:
If a quadratic trinomial has a leading coefficient of 1 and a positive constant, then it is very easy to factor.
You just have to look for two factors of the constant term that add up to the coefficient of x( the middle term).
Then you write as factors.
For instance;
To factors of 6 that add up to 5 are 2 and 3.
Therefore the factorization is: