A.) An equilateral triangle has three lines of symmetry. It has rotational symmetry of order 3. It has three equal sides.
b.) A Square (4 sides) has 4 Lines of Symmetry.
c.) A Regular Hexagon (6 sides) has 6 Lines of Symmetry
the first step Andre made was
2x+6=3x-8
or, -x+6=-8
And the first step Diego made was
2x+6=3x-8
or, +6=3x-2x
or, 6=x-8
...
You can multiply 0.129 and 0.3 by 10 each to make it a little easier to see what to do.
0.129 / 0.3 = 1.29 / 3
Simple long division will take you to 0.43