Answer:
The first question is the third choice. Divide by two to get proper squaring. Anytime there is a number in front of the x in a situation like that, always divide by that number on both sides first. Then go from there.
The second question is also the third choice. The square root of 64 is 8. It can't be negative because square rooting is always positive unless you want a weird "i" in there. That's for algebra 2 and beyond so don't worry about it mate.
Answer:
9/20
Step-by-step explanation:
Answer:

Step-by-step explanation:
Given

Required
Determine 

Open bracket

Equate the equation to 0

Express 3 as 1 + 1 + 1

Collect like terms

Group each terms

Factorize (starting with the first bracket)












Express 0 as 0 + 0 + 0

By comparison



Solving for 
Take square root of both sides

Add 1 to both sides


Solving for 
Take square root of both sides

Subtract 1 from both sides


Solving for 
Take square root of both sides

Subtract 1 from both sides


Substitute the values of a, b and c in 



Answer:
C is correct
Step-by-step explanation:
3+6=9
2 sides on a triangle must be greater than the other side