Which of the following completes the square for the equation below? x^2+18x=0

Let's make the equation equal something other than 0. Let's subtract 18x from both sides.
X²=-18x
By looking at this, I can findn what x is. Since one side is a number times itself equals -18 times something else. X has to be negative 18. Let's try it.
(-18)²=-18×-18
324=324
Now let's put it into the equation.
(-18)²+18(-18)=0
324-324=0
0=0
This is the same thing, since being squared is the number multiplied by itself.
So, x equals -18. 

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post