Double angle (or half angle, depending how you look at it) identities:



So we have



Note that when taking the square root, we should take into account that that could yield two possible solutions, but we know
and
, so it's also the case that
.
Also, the reason we have equality in the last step can be explained like so:

(not unlike the process used to complete the square)
7 3/4.
i got this by adding 1/5+2/5=3/4 and then 4+3 which are the whole numbers.
Hello,
So the original temperature was 7 degrees Celsius.
Then, it went down 10 degrees.
7-10= -3
So, in this case, the answer is C) -3 degrees celsius
the answer is 3/5
if that's not right I apologize
Answer:
prolly 1.5 too lol
Step-by-step explanation: