# Maths Reflection for Semester 2

This year, I set a goal to improve on my algebra. I believe that I have achieved this goal very well. Some of the many things I’ve learnt are to solve an equation with more than one unknown value. e.g.
3D + 2d = 32kg  –>you turn one of the unknown into the same number.
4D + 3d = 44kg                  which means that it’s  9D + 6d = 96kg
__________________________________-8D – 6d = -88kg —> you subtract the equations from each other, turning the second one into negatives.
___________________________________1D            = 8kg.
You now focus on the second sum which is 4D + 3d = 44kg. You solve it by :
(4×8) + 3d = 44kg
=32 + 3d = 44kg.
You then subtract the two given values like a normal algebraic equation:
32 + 3d = 44kg
3d =44 – 32
3d = 12  —> because you want to find out what 1d is, you divide the 12 by three. That gives you 4.
Your two formulas for the sum are:
1D = 8kg
1d = 4kg
Another thing I learnt was to find the number of degrees in each angle of a polygon. The formula to that is:
(n-2) x 180 —> ‘n’ being the number of sides in the polygon.
_______n
I found this very interesting because finding the angle to more complex polygons like octagons and heptagons. Because of these shapes finding the exact number of degrees in the shape is a lot more complicated than the simpler shapes.