The answer to this is A. 40
Answer:
No
Step-by-step explanation:
she should have just factored x² - 6x - 7 = 0
(x + 1)(x - 7) = 0
x = -1, x = 7
Answer:
2:1.
Step-by-step explanation:
The area of a red curved surface = 2πr^2.
The area of the yellow flat surface = πr^2.
This is the case for all the hemispheres.
Therefore the required ratio = 2πr^2 : πr^2
= 2:1.
Answer:
The nth term is given by: 
The 30th term is 78.
Step-by-step explanation:
Arithmetic sequence:
The nth term of an arithmetic sequence is given by:
In which 
is the first term and d is the common difference between terms.
-9, -6, - 3,0
This means that 
. So
30th term:
The 30th term is 78.
Answer:
Step-by-step explanation:
<u>It shows combination of:</u>
- m∡EBD = 180° and
- m∡EBC + m∡CBA + m∡DBA = m∡EBD
<u>m∡EBD in the first equation is substituted with 180° in the second and it results in:</u>
- m∡EBC + m∡CBA + m∡DBA = 180°
<u>Correct choice is:</u>
