Just watch videos on youtube.
Using the quadratic formula, the answers could be A B and D
To determine what percentage of 642 the number 321 is, we can follow the equation below.
(Smaller Number / Bigger Number)*100
We can plug the numbers into the equation to get our answer.
(321/642)*100 = 0.5 *(100) = 50%
So 321 is 50% of 642