<span>The <u>correct answer</u> is:
The midpoint of a segment.
Explanation<span>:
To construct a line parallel to another line through a given point, the first thing you do is fold the given line onto itself, making sure that the given point is on the fold. This is the same construction used to find the midpoint of a segment.
Unfold the paper, and the crease made with the fold creates a line through the given point and given line. Fold this new line (crease) onto itself, making sure the given point is in the fold. This is again the same construction used to find the midpoint of a segment, and this creates our parallel line through our given point.</span></span>
It should be |-80+15|=65 units because absolute value makes it positive.
I'm not sure which numbers you are referring to, but 3 has the same absolute value as -3, and 7 has the same absolute value as -7, just for an example.
1) 4√3 - 24√3 = -20√3
2) Multiply and simplify square root of 3 times the quantity of 4 + square root of 12:
(√3) x 4 + √12==> (√3) x 4 + √(4 x 3)==> 4√3 + 2√3 = 6√3
3) Simplify √3 + 4√3. ===> =5√3