10 + 10 = 20
20 + 10 = 30
30 + 10 = 40
(And so on.)
Can you help me with my stuff please
Answer:

Step-by-step explanation:
<u>Alternating Sequences</u>
A sequence whose terms alternate in the sign is called an alternating sequence.
The given sequence consists of the numbers -6 and 6 in infinite alternation.
Such sequences can be expressed as equations of the form

Where a is the constant absolute value of each term and m is an expression adequately arranged to reproduce the alternation of signs.
Since the sign is minus for odd terms, and plus for even terms, m=n is a good expression for m. Thus:

Answer:
c=27/40
in decimal form 0.675
Step-by-step explanation:
1/8+c=4/5
c=4/5
-1/8
c=27/40