Afamily has 8 girls and 4 boys. a total of 3 children must be chosen to speak on behalf of the family at a local benefit. what is the probability that no girls and 3 boys will be chosen?

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.  

11) obtuse

13)right

15) acute