Start by putting two coins on each side of the scale. If one side is higher, then the light coin must be in that pair (use a second weighing to determine which of that pair is the lightest.)
If the initial weighing shows the two pairs to be even, discard those four and go to the three others. Put two of the coins on the scale - one on each side. If one side stays higher, that coin is your light one. If however they are equal, the final unweighed coin must be the lighter coin.
Answer: 1245 :)
Step-by-step explanation:
Answer:
(3 (pm) sqrt(7))/2
Step-by-step explanation:
First step: Identify a,b, and c
a=2
b=-6
c=1
Second step: Find b^2-4ac (this is called the discriminant-I will call this D)
(-6)^2-4(2)(1)=36-8=28
Third step: Find the square root of the discriminant aka sqrt(D)
sqrt(28)
Let's see if we can simplify sqrt(28)
Here is there a factor of 28 that is a perfect square? How about 4? Yep!
sqrt(28)=sqrt(4)sqrt(7)=2sqrt(7).
Fourth Step: What is -b? If b=-6 then -b=6.
Fifth step: What is 2a? 2(2)=4
So the formula is
x=(-b (pm) sqrt(D))/(2a)
or
x=(step4 (pm) step 3)/(step 5)
x=(6 (pm) 2sqrt(7))/4
Simplify
x=(3 (pm) sqrt(7))/2
*pm means plus or minus
*sqrt( ) means square root of the number that follows in the ( )
The common denominator would be 1!
